Mitigation of methane emission from an old unlined landfill in Klintholm, Denmark using a passive biocover system.

PubMed

Scheutz, Charlotte; Pedersen, Rasmus Broe; Petersen, Per Haugsted; Jørgensen, Jørgen Henrik Bjerre; Ucendo, Inmaculada Maria Buendia; Mønster, Jacob G; Samuelsson, Jerker; Kjeldsen, Peter

2014-07-01

Methane generated at landfills contributes to global warming and can be mitigated by biocover systems relying on microbial methane oxidation. As part of a closure plan for an old unlined landfill without any gas management measures, an innovative biocover system was established. The system was designed based on a conceptual model of the gas emission patterns established through an initial baseline study. The study included construction of gas collection trenches along the slopes of the landfill where the majority of the methane emissions occurred. Local compost materials were tested as to their usefulness as bioactive methane oxidizing material and a suitable compost mixture was selected. Whole site methane emission quantifications based on combined tracer release and downwind measurements in combination with several local experimental activities (gas composition within biocover layers, flux chamber based emission measurements and logging of compost temperatures) proved that the biocover system had an average mitigation efficiency of approximately 80%. The study showed that the system also had a high efficiency during winter periods with temperatures below freezing. An economic analysis indicated that the mitigation costs of the biocover system were competitive to other existing greenhouse gas mitigation options. Copyright © 2014 Elsevier Ltd. All rights reserved.

A techno-economic & environmental analysis of a novel technology utilizing an internal combustion engine as a compact, inexpensive micro-reformer for a distributed gas-to-liquids system

NASA Astrophysics Data System (ADS)

Browne, Joshua B.

Anthropogenic greenhouse gas emissions (GHG) contribute to global warming, and must be mitigated. With GHG mitigation as an overarching goal, this research aims to study the potential for newfound and abundant sources of natural gas to play a role as part of a GHG mitigation strategy. However, recent work suggests that methane leakage in the current natural gas system may inhibit end-use natural gas as a robust mitigation strategy, but that natural gas as a feedstock for other forms of energy, such as electricity generation or liquid fuels, may support natural-gas based mitigation efforts. Flaring of uneconomic natural gas, or outright loss of natural gas to the atmosphere results in greenhouse gas emissions that could be avoided and which today are very large in aggregate. A central part of this study is to look at a new technology for converting natural gas into methanol at a unit scale that is matched to the size of individual natural gas wells. The goal is to convert stranded or otherwise flared natural gas into a commercially valuable product and thereby avoid any unnecessary emission to the atmosphere. A major part of this study is to contribute to the development of a novel approach for converting natural gas into methanol and to assess the environmental impact (for better or for worse) of this new technology. This Ph. D. research contributes to the development of such a system and provides a comprehensive techno-economic and environmental assessment of this technology. Recognizing the distributed nature of methane leakage associated with the natural gas system, this work is also intended to advance previous research at the Lenfest Center for Sustainable Energy that aims to show that small, modular energy systems can be made economic. This thesis contributes to and analyzes the development of a small-scale gas-to-liquids (GTL) system aimed at addressing flared natural gas from gas and oil wells. This thesis includes system engineering around a design that converts natural gas to synthesis gas (syngas) in a reciprocating internal combustion engine and then converts the syngas into methanol in a small-scale reactor. With methanol as the product, this research aims to show that such a system can not only address current and future natural gas flaring regulation, but eventually can compete economically with historically large-scale, centralized methanol production infrastructure. If successful, such systems could contribute to a shift away from large, multi-billion dollar capital cost chemical plants towards smaller systems with shorter lifetimes that may decrease the time to transition to more sustainable forms of energy and chemical conversion technologies. This research also quantifies the potential for such a system to contribute to mitigating GHG emissions, not only by addressing flared gas in the near-term, but also supporting future natural gas infrastructure ideas that may help to redefine the way the current natural gas pipeline system is used. The introduction of new, small-scale, distributed energy and chemical conversion systems located closer to the point of extraction may contribute to reducing methane leakage throughout the natural gas distribution system by reducing the reliance and risks associated with the aging natural gas pipeline infrastructure. The outcome of this thesis will result in several areas for future work. From an economic perspective, factors that contribute to overall system cost, such as operation and maintenance (O&M) and capital cost multiplier (referred to as the Lang Factor for large-scale petro-chemical plants), are not yet known for novel systems such as the technology presented here. From a technical perspective, commercialization of small-scale, distributed chemical conversion systems may create a demand for economical compression and air-separation technologies at this scale that do not currently exist. Further, new business cases may arise aimed at utilizing small, remote sources of methane, such as biogas from agricultural and municipal waste. Finally, while methanol was selected as the end-product for this thesis, future applications of this technology may consider methane conversion to hydrogen, ammonia, and ethylene for example, challenging the orthodoxy in the chemical industry that "bigger is better."

Mitigation options for methane emissions from rice fields in the Philippines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lantin, R.S.; Buendia, L.V.; Wassmann, R.

1996-12-31

The contribution of Philippine rice production to global methane emission and breakthroughs in methane emission studies conducted in the country are presented in this paper. A significant impact in the reduction of GHG emissions from agriculture can be achieved if methane emissions from ricefields can be abated. This study presents the contribution of Philippine rice cultivation to global methane emission and breakthroughs in methane emission studies in the country which address the issue of mitigation. Using the derived emission factors from local measurements, rice cultivation contributes 566.6 Gg of methane emission in the Philippines. This value is 62% of themore » total methane emitted from the agriculture sector. The emission factors employed which are 78% of the IPCC value for irrigated rice and 95% for rainfed rice were derived from measurements with an automatic system taken during the growth duration in the respective ecosystems. Plots drained for 2 weeks at midtillering and before harvest gave a significant reduction in methane emission as opposed to continuously flooded plots and plots drained before harvest. The cultivar Magat reduced methane emission by 50% as compared to the check variety IR72. The application of ammonium sulfate instead of urea reduced methane emission by 10% to 34%. Addition of 6 t ha{sup {minus}1} phosphogypsum in combination with urea reduced emission by 74% as opposed to plots applied with urea alone. It is also from the results of such measurements that abatement strategies are based as regards to modifying treatments such as water management, fertilization, and choice of rice variety. It is not easy to identify and recommend mitigation strategies that will fit a particular cropping system. However, the identified mitigation options provide focus for the abatement of methane emission from ricefields.« less

Methane Leakage from Oil & Gas Operations. What have we learned from recent studies in the U.S.?

NASA Astrophysics Data System (ADS)

Zavala-Araiza, Daniel; Hamburg, Steven

2016-04-01

Methane, the principal component of natural gas, is a powerful greenhouse gas. Methane losses from the natural gas supply chain erode the climate benefits of fuel switching to natural gas from other fossil fuels, reducing or eliminating them for several decades or longer. Global data on methane emissions from the oil and gas sector is uncertain and as a consequence, measuring and characterizing methane emissions is critical to the design of effective mitigation strategies. In this work, we synthesize lessons learned from dozens of U.S. studies that characterized methane emissions along each stage of the natural gas supply chain. These results are relevant to the design of methane measurement campaigns outside the U.S. A recurring theme in the research conducted in the U.S. is that public emissions inventories (e.g., The U.S. Environmental Protection Agency's National Greenhouse gas Inventory) tend to underestimate emissions for two key reasons: (1) use of non-representative emission factors and (2) inaccurate activity data (incomplete counts of facilities and equipment). Similarly, the accuracy of emission factors and the effectiveness of mitigation strategies are heavily affected by the existence of low-probability, unpredictable high emitters-which have been observed all along the supply chain- and are spatiotemporally variable. We conducted a coordinated campaign to measure methane emissions in a major gas producing region of the U.S. (Barnett Shale region of Texas) using a diversity of approaches. As part of this study we identified methods for effective quantification of regional fossil methane emissions using atmospheric data (through replicate mass balance flights and source apportionment using methane to ethane ratios) as well as how to build an accurate inventory that includes a statistical estimator that more rigorously captures the magnitude and frequency of high emitters. We found agreement between large-scale atmospheric sampling estimates and source-based estimates (custom inventory). With measured oil and gas methane being roughly twice what estimates based on the U.S. Environmental Protection Agency's National Greenhouse gas Inventory would suggest. Ten percent of oil and gas facilities in the region -the high emitters or fat tail of the distribution- account for 90% of the emissions. We observed significant regional heterogeneity (e.g., local practices, technologies used, physical properties of the reservoirs) during the production, processing, transportation, and use of natural gas, describing this heterogeneity is critical to constructing accurate methane emission inventories. The lessons learned in the U.S. provide robust methodological guidelines that can be used to extend our understanding of the climatic implications of global oil and gas methane emissions with regards to, accurate quantification, reporting, and mitigation of methane emissions.

Pressure-relief and methane production performance of pressure relief gas extraction technology in the longwall mining

NASA Astrophysics Data System (ADS)

Zhang, Cun; Tu, Shihao; Chen, Min; Zhang, Lei

2017-02-01

Pressure relief gas extraction technology (PRGET) has been successfully implemented at many locations as a coal mine methane exploitation and outburst prevention technology. Comprehensive PRGET including gob gas venthole (GGV), crossing seam drilling hole (CSDH), large diameter horizontal long drilling hole (LDHLDH) and buried pipe for extraction (BPE) have been used to extract abundant pressure-relief methane (PRM) during protective coal seam mining; these techniques mitigated dangers associated with coal and gas outbursts in 13-1 coal seam mining in the Huainan coalfield. These extraction technologies can ensure safe protective seam mining and effectively extract coal and gas. This article analyses PRGET production performance and verifies it with the field measurement. The results showed that PRGET drilling to extract PRM from the protected coal seam significantly reduced methane emissions from a longwall ventilation system and produced highly efficient extraction. Material balance analyses indicated a significant decrease in gas content and pressure in the protected coal seam, from 8.78 m3 t-1 and 4.2 MPa to 2.34 m3 t-1 and 0.285 MPa, respectively. The field measurement results of the residual gas content in protected coal seam (13-1 coal seam) indicated the reliability of the material balance analyses and the pressure relief range of PRGET in the protected coal seam is obtained.

Global health benefits of mitigating ozone pollution with methane emission controls.

PubMed

West, J Jason; Fiore, Arlene M; Horowitz, Larry W; Mauzerall, Denise L

2006-03-14

Methane (CH(4)) contributes to the growing global background concentration of tropospheric ozone (O(3)), an air pollutant associated with premature mortality. Methane and ozone are also important greenhouse gases. Reducing methane emissions therefore decreases surface ozone everywhere while slowing climate warming, but although methane mitigation has been considered to address climate change, it has not for air quality. Here we show that global decreases in surface ozone concentrations, due to methane mitigation, result in substantial and widespread decreases in premature human mortality. Reducing global anthropogenic methane emissions by 20% beginning in 2010 would decrease the average daily maximum 8-h surface ozone by approximately 1 part per billion by volume globally. By using epidemiologic ozone-mortality relationships, this ozone reduction is estimated to prevent approximately 30,000 premature all-cause mortalities globally in 2030, and approximately 370,000 between 2010 and 2030. If only cardiovascular and respiratory mortalities are considered, approximately 17,000 global mortalities can be avoided in 2030. The marginal cost-effectiveness of this 20% methane reduction is estimated to be approximately 420,000 US dollars per avoided mortality. If avoided mortalities are valued at 1 US dollars million each, the benefit is approximately 240 US dollars per tone of CH(4) ( approximately 12 US dollars per tone of CO(2) equivalent), which exceeds the marginal cost of the methane reduction. These estimated air pollution ancillary benefits of climate-motivated methane emission reductions are comparable with those estimated previously for CO(2). Methane mitigation offers a unique opportunity to improve air quality globally and can be a cost-effective component of international ozone management, bringing multiple benefits for air quality, public health, agriculture, climate, and energy.

Methane Trace-Gas Sensing Enabled by Silicon Photonic Integration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Green, William

Fugitive methane leaks occurring during extraction at typical natural gas wells have an adverse environmental impact due to the methane’s large radiative forcing, in addition to reducing the producer’s overall efficiency and cost. Mitigation of these concerns can benefit from cost-effective sensor nodes, performing reliable, rapid and continuous tracking of methane emissions. The efficacy of laser spectroscopy has been widely demonstrated in both environmental and medical applications due to its sensitivity and specificity to the target analyte. However, the present cost and lack of manufacturing scalability of traditional free-space optical systems can limit their viability for deployment in economical wide-areamore » sensor networks. This presentation will review the development and performance of a cost-effective silicon photonic trace gas sensing platform that leverages silicon photonic waveguide and packaging technologies to perform on-chip evanescent field spectroscopy of methane.« less

The Impact of Advanced Greenhouse Gas Measurement Science on Policy Goals and Research Strategies

NASA Astrophysics Data System (ADS)

Abrahams, L.; Clavin, C.; McKittrick, A.

2016-12-01

In support of the Paris agreement, accurate characterizations of U.S. greenhouse gas (GHG) emissions estimates have been area of increased scientific focus. Over the last several years, the scientific community has placed significant emphasis on understanding, quantifying, and reconciling measurement and modeling methods that characterize methane emissions from petroleum and natural gas sources. This work has prompted national policy discussions and led to the improvement of regional and national methane emissions estimates. Research campaigns focusing on reconciling atmospheric measurements ("top-down") and process-based emissions estimates ("bottom-up") have sought to identify where measurement technology advances could inform policy objectives. A clear next step is development and deployment of advanced detection capabilities that could aid U.S. emissions mitigation and verification goals. The breadth of policy-relevant outcomes associated with advances in GHG measurement science are demonstrated by recent improvements in the petroleum and natural gas sector emission estimates in the EPA Greenhouse Gas Inventory, ambitious efforts to apply inverse modeling results to inform or validate national GHG inventory, and outcomes from federal GHG measurement science technology development programs. In this work, we explore the variety of policy-relevant outcomes impacted by advances in GHG measurement science, with an emphasis on improving GHG inventory estimates, identifying emissions mitigation strategies, and informing technology development requirements.

Methanogens: Methane Producers of the Rumen and Mitigation Strategies

PubMed Central

Hook, Sarah E.; Wright, André-Denis G.; McBride, Brian W.

2010-01-01

Methanogens are the only known microorganisms capable of methane production, making them of interest when investigating methane abatement strategies. A number of experiments have been conducted to study the methanogen population in the rumen of cattle and sheep, as well as the relationship that methanogens have with other microorganisms. The rumen methanogen species differ depending on diet and geographical location of the host, as does methanogenesis, which can be reduced by modifying dietary composition, or by supplementation of monensin, lipids, organic acids, or plant compounds within the diet. Other methane abatement strategies that have been investigated are defaunation and vaccines. These mitigation methods target the methanogen population of the rumen directly or indirectly, resulting in varying degrees of efficacy. This paper describes the methanogens identified in the rumens of cattle and sheep, as well as a number of methane mitigation strategies that have been effective in vivo. PMID:21253540

Potential impact of salinity on methane production from food waste anaerobic digestion.

PubMed

Zhao, Jianwei; Liu, Yiwen; Wang, Dongbo; Chen, Fei; Li, Xiaoming; Zeng, Guangming; Yang, Qi

2017-09-01

Previous studies have demonstrated that the presence of sodium chloride (NaCl) inhibited the production of methane from food waste anaerobic digestion. However, the details of how NaCl affects methane production from food waste remain unknown by now and the efficient approach to mitigate the impact of NaCl on methane production was seldom reported. In this paper, the details of how NaCl affects methane production was first investigated via a series of batch experiments. Experimental results showed the effect of NaCl on methane production was dosage dependent. Low level of NaCl improved the hydrolysis and acidification but inhibited the process of methanogenesis whereas high level of NaCl inhibit both steps of acidification and methanogenesis. Then an efficient approach, i.e. co-digestion of food waste and waste activated sludge, to mitigate the impact of NaCl on methane production was reported. Finally, the mechanisms of how co-digestion mitigates the effect on methane production caused by NaCl in co-digestion system were revealed. These findings obtained in this work might be of great importance for the operation of methane recovery from food waste in the presence of NaCl. Copyright © 2017 Elsevier Ltd. All rights reserved.

Efficient 1.6 Micron Laser Source for Methane DIAL

NASA Technical Reports Server (NTRS)

Shuman, Timothy; Burnham, Ralph; Nehrir, Amin R.; Ismail, Syed; Hair, Johnathan W.

2013-01-01

Methane is a potent greenhouse gas and on a per molecule basis has a warming influence 72 times that of carbon dioxide over a 20 year horizon. Therefore, it is important to look at near term radiative effects due to methane to develop mitigation strategies to counteract global warming trends via ground and airborne based measurements systems. These systems require the development of a time-resolved DIAL capability using a narrow-line laser source allowing observation of atmospheric methane on local, regional and global scales. In this work, a demonstrated and efficient nonlinear conversion scheme meeting the performance requirements of a deployable methane DIAL system is presented. By combining a single frequency 1064 nm pump source and a seeded KTP OPO more than 5 mJ of 1.6 µm pulse energy is generated with conversion efficiencies in excess of 20%. Even without active cavity control instrument limited linewidths (50 pm) were achieved with an estimated spectral purity of 95%. Tunable operation over 400 pm (limited by the tuning range of the seed laser) was also demonstrated. This source demonstrated the critical needs for a methane DIAL system motivating additional development of the technology.

Need for a marginal methodology in assessing natural gas system methane emissions in response to incremental consumption.

PubMed

Mac Kinnon, Michael; Heydarzadeh, Zahra; Doan, Quy; Ngo, Cuong; Reed, Jeff; Brouwer, Jacob

2018-05-17

Accurate quantification of methane emissions from the natural gas system is important for establishing greenhouse gas inventories and understanding cause and effect for reducing emissions. Current carbon intensity methods generally assume methane emissions are proportional to gas throughput so that increases in gas consumption yield linear increases in emitted methane. However, emissions sources are diverse and many are not proportional to throughput. Insights into the causal drivers of system methane emissions, and how system-wide changes affect such drivers are required. The development of a novel cause-based methodology to assess marginal methane emissions per unit of fuel consumed is introduced. The carbon intensities of technologies consuming natural gas are critical metrics currently used in policy decisions for reaching environmental goals. For example, the low-carbon fuel standard in California uses carbon intensity to determine incentives provided. Current methods generally assume methane emissions from the natural gas system are completely proportional to throughput. The proposed cause-based marginal emissions method will provide a better understanding of the actual drivers of emissions to support development of more effective mitigation measures. Additionally, increasing the accuracy of carbon intensity calculations supports the development of policies that can maximize the environmental benefits of alternative fuels, including reducing greenhouse gas emissions.

Of Detection Limits and Effective Mitigation: The Use of Infrared Cameras for Methane Leak Detection

NASA Astrophysics Data System (ADS)

Ravikumar, A. P.; Wang, J.; McGuire, M.; Bell, C.; Brandt, A. R.

2017-12-01

Mitigating methane emissions, a short-lived and potent greenhouse gas, is critical to limiting global temperature rise to two degree Celsius as outlined in the Paris Agreement. A major source of anthropogenic methane emissions in the United States is the oil and gas sector. To this effect, state and federal governments have recommended the use of optical gas imaging systems in periodic leak detection and repair (LDAR) surveys to detect for fugitive emissions or leaks. The most commonly used optical gas imaging systems (OGI) are infrared cameras. In this work, we systematically evaluate the limits of infrared (IR) camera based OGI system for use in methane leak detection programs. We analyze the effect of various parameters that influence the minimum detectable leak rates of infrared cameras. Blind leak detection tests were carried out at the Department of Energy's MONITOR natural gas test-facility in Fort Collins, CO. Leak sources included natural gas wellheads, separators, and tanks. With an EPA mandated 60 g/hr leak detection threshold for IR cameras, we test leak rates ranging from 4 g/hr to over 350 g/hr at imaging distances between 5 ft and 70 ft from the leak source. We perform these experiments over the course of a week, encompassing a wide range of wind and weather conditions. Using repeated measurements at a given leak rate and imaging distance, we generate detection probability curves as a function of leak-size for various imaging distances, and measurement conditions. In addition, we estimate the median detection threshold - leak-size at which the probability of detection is 50% - under various scenarios to reduce uncertainty in mitigation effectiveness. Preliminary analysis shows that the median detection threshold varies from 3 g/hr at an imaging distance of 5 ft to over 150 g/hr at 50 ft (ambient temperature: 80 F, winds < 4 m/s). Results from this study can be directly used to improve OGI based LDAR protocols and reduce uncertainty in estimated mitigation effectiveness. Furthermore, detection limits determined in this study can be used as standards to compare new detection technologies.

Methods for Finding Legacy Wells in Residential and Commercial Areas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hammack, Richard W.; Veloski, Garret A.

In 1919, the enthusiasm surrounding a short-lived gas play in Versailles Borough, Pennsylvania resulted in the drilling of many needless wells. The legacy of this activity exists today in the form of abandoned, unplugged gas wells that are a continuing source of fugitive methane in the midst of a residential and commercial area. Flammable concentrations of methane have been detected near building foundations, which have forced people from their homes and businesses until methane concentrations decreased. Despite mitigation efforts, methane problems persist and have caused some buildings to be permanently abandoned and demolished. This paper describes the use of magneticmore » and methane sensing methods by the National Energy Technology Laboratory (NETL) to locate abandoned gas wells in Versailles Borough where site access is limited and existing infrastructure can interfere. Here, wells are located between closely spaced houses and beneath buildings and parking lots. Wells are seldom visible, often because wellheads and internal casing strings have been removed, and external casing has been cut off below ground level. The magnetic survey of Versailles Borough identified 53 strong, monopole magnetic anomalies that are presumed to indicate the locations of steel-cased wells. This hypothesis was tested by excavating the location of one strong, monopole magnetic anomaly that was within an area of anomalous methane concentrations. The excavation uncovered an unplugged gas well that was within 0.2 m of the location of the maximum magnetic signal. Truck-mounted methane surveys of Versailles Borough detected numerous methane anomalies that were useful for narrowing search areas. Methane sources identified during truck-mounted surveys included strong methane sources such as sewers and methane mitigation vents. However, inconsistent wind direction and speed, especially between buildings, made locating weaker methane sources (such as leaking wells) difficult. Walking surveys with the methane detector mounted on a cart or wagon were more effective for detecting leaking wells because the instrument’s air inlet was near the ground where: 1) the methane concentration from subsurface sources (including wells) was a maximum, and 2) there was less displacement of methane anomalies from methane sources by air currents. The Versailles Borough survey found 15 methane anomalies that coincided with the location of well-type magnetic anomalies; the methane sources for these anomalies were assumed to be leaking wells. For abandoned well locations where the wellhead and all casing strings have been removed and there is no magnetic anomaly, leaking wellbores can sometimes be detected by methane surveys. Unlike magnetic anomalies, methane anomalies can be: 1) ephemeral, 2) significantly displaced from the well location, and 3) from non-well sources that cannot be discriminated without isotopic analysis. If methane surveys are used for well location, the air inlet to the instrument should be kept as close to the ground as possible to minimize the likelihood of detecting methane from distant, wind-blown sources.« less

Utilization of heat from High Temperature Reactors (HTR) for dry reforming of methane

NASA Astrophysics Data System (ADS)

Jastrząb, Krzysztof

2018-01-01

One of the methods for utilization of waste carbon dioxide consists in reaction of methane with carbon dioxide, referred to as dry reforming of methane. It is an intensely endothermic catalytic process that takes place at the temperature above 700°C. Reaction of methane with carbon dioxide leads to formation of synthesis gas (syngas) that is a valuable chemical raw material. The energy that is necessary for the process to take place can be sourced from High Temperature Nuclear Reactors (HTR). The completed studies comprises a series of thermodynamic calculations and made it possible to establish optimum conditions for the process and demand for energy from HTR units. The dry reforming of methane needs also a catalytic agent with appropriate activity, therefore the hydrotalcite catalyser with admixture of cerium and nickel, developed at AGH University of Technology seems to be a promising solution. Thus, the researchers from the Institute for Chemical Processing of Coal (IChPW) in Zabrze have developed a methodology for production of the powdery hydrotalcite catalyser and investigated catalytic properties of the granulate obtained. The completed experiments confirmed that the new catalyser demonstrated high activity and is suitable for the process of methane dry reforming. In addition, optimum parameters of the were process (800°C, CO2:CH4 = 3:1) were established as well. Implementation of the technology in question into industrial practice, combined with utilization of HTR heat can be a promising method for management of waste carbon dioxide and may eventually lead to mitigation of the greenhouse effect.

Survey of Constellation-Era LOX/Methane Development Activities and Future Development Needs

NASA Technical Reports Server (NTRS)

Marshall, William M.; Stiegemeier, Benjamin; Greene, Sandra Elam; Hurlbert, Eric A.

2017-01-01

NASA formed the Constellation Program in 2005 to achieve the objectives of maintaining American presence in low-Earth orbit, returning to the moon for purposes of establishing an outpost, and laying the foundation to explore Mars and beyond in the first half of the 21st century. The Exploration Technology Development Program (ETDP) was formulated to address the technology needs to address Constellation architecture decisions. The Propellants and Cryogenic Advanced Development (PCAD) project was tasked with risk mitigation of specific propulsion related technologies to support ETDP. Propulsion systems were identified as critical technologies owing to the high gear-ratio of lunar Mars landers Cryogenic propellants offer performance advantage over storables (NTOMMH) Mass savings translate to greater payload capacity In-situ production of propellant an attractive feature; methane and oxygen identified as possible Martian in-situ propellants New technologies were required to meet more difficult missions High performance LOX/LH2 deep throttle descent engines High performance LOX/LCH4 ascent main and reaction control system (RCS) engines The PCAD project sought to provide those technologies through Reliable ignition pulse RCS Fast start High efficiency engines Stable deep throttling.

International Space Exploration Coordination Group Assessment of Technology Gaps for Dust Mitigation for the Global Exploration Roadmap

NASA Technical Reports Server (NTRS)

Gaier, James R.; Vangen, Scott; Abel, Phil; Agui, Juan; Buffington, Jesse; Calle, Carlos; Mary, Natalie; Smith, Jonathan Drew; Straka, Sharon; Mugnuolo, Raffaele;

Addressing biogenic greenhouse gas emissions from hydropower in LCA.

PubMed

Hertwich, Edgar G

2013-09-03

The ability of hydropower to contribute to climate change mitigation is sometimes questioned, citing emissions of methane and carbon dioxide resulting from the degradation of biogenic carbon in hydropower reservoirs. These emissions are, however, not always addressed in life cycle assessment, leading to a bias in technology comparisons, and often misunderstood. The objective of this paper is to review and analyze the generation of greenhouse gas emissions from reservoirs for the purpose of technology assessment, relating established emission measurements to power generation. A literature review, data collection, and statistical analysis of methane and CO2 emissions are conducted. In a sample of 82 measurements, methane emissions per kWh hydropower generated are log-normally distributed, ranging from micrograms to 10s of kg. A multivariate regression analysis shows that the reservoir area per kWh electricity is the most important explanatory variable. Methane emissions flux per reservoir area are correlated with the natural net primary production of the area, the age of the power plant, and the inclusion of bubbling emissions in the measurement. Even together, these factors fail to explain most of the variation in the methane flux. The global average emissions from hydropower are estimated to be 85 gCO2/kWh and 3 gCH4/kWh, with a multiplicative uncertainty factor of 2. GHG emissions from hydropower can be largely avoided by ceasing to build hydropower plants with high land use per unit of electricity generated.

The California Baseline Methane Survey

NASA Astrophysics Data System (ADS)

Duren, R. M.; Thorpe, A. K.; Hopkins, F. M.; Rafiq, T.; Bue, B. D.; Prasad, K.; Mccubbin, I.; Miller, C. E.

2017-12-01

The California Baseline Methane Survey is the first systematic, statewide assessment of methane point source emissions. The objectives are to reduce uncertainty in the state's methane budget and to identify emission mitigation priorities for state and local agencies, utilities and facility owners. The project combines remote sensing of large areas with airborne imaging spectroscopy and spatially resolved bottom-up data sets to detect, quantify and attribute emissions from diverse sectors including agriculture, waste management, oil and gas production and the natural gas supply chain. Phase 1 of the project surveyed nearly 180,000 individual facilities and infrastructure components across California in 2016 - achieving completeness rates ranging from 20% to 100% per emission sector at < 5 meters spatial resolution. Additionally, intensive studies of key areas and sectors were performed to assess source persistence and variability at times scales ranging from minutes to months. Phase 2 of the project continues with additional data collection in Spring and Fall 2017. We describe the survey design and measurement, modeling and analysis methods. We present initial findings regarding the spatial, temporal and sectoral distribution of methane point source emissions in California and their estimated contribution to the state's total methane budget. We provide case-studies and lessons learned about key sectors including examples where super-emitters were identified and mitigated. We summarize challenges and recommendations for future methane research, inventories and mitigation guidance within and beyond California.

Mitigation of Humic Acid Inhibition in Anaerobic Digestion of Cellulose by Addition of Various Salts.

PubMed

Azman, Samet; Khadem, Ahmad F; Zeeman, Grietje; van Lier, Jules B; Plugge, Caroline M

2015-03-25

Humic compounds are inhibitory to the anaerobic hydrolysis of cellulosic biomass. In this study, the impact of salt addition to mitigate the inhibitory effects of humic compounds was investigated. The experiment was conducted using batch tests to monitor the anaerobic hydrolysis of cellulose in the presence of humic acid. Sodium, potassium, calcium, magnesium and iron salts were tested separately for their efficiency to mitigate humic acid inhibition. All experiments were done under mesophilic conditions (30 °C) and at pH 7. Methane production was monitored online, using the Automatic Methane Potential Test System. Methane production, soluble chemical oxygen demand and volatile fatty acid content of the samples were measured to calculate the hydrolysis efficiencies. Addition of magnesium, calcium and iron salts clearly mitigated the inhibitory effects of humic acid and hydrolysis efficiencies reached up to 75%, 65% and 72%, respectively, which were similar to control experiments. Conversely, potassium and sodium salts addition did not mitigate the inhibition and hydrolysis efficiencies were found to be less than 40%. Mitigation of humic acid inhibition via salt addition was also validated by inductively coupled plasma atomic emission spectroscopy analyses, which showed the binding capacity of different cations to humic acid.

Mitigation of Humic Acid Inhibition in Anaerobic Digestion of Cellulose by Addition of Various Salts

PubMed Central

Azman, Samet; Khadem, Ahmad F.; Zeeman, Grietje; van Lier, Jules B.; Plugge, Caroline M.

2015-01-01

Humic compounds are inhibitory to the anaerobic hydrolysis of cellulosic biomass. In this study, the impact of salt addition to mitigate the inhibitory effects of humic compounds was investigated. The experiment was conducted using batch tests to monitor the anaerobic hydrolysis of cellulose in the presence of humic acid. Sodium, potassium, calcium, magnesium and iron salts were tested separately for their efficiency to mitigate humic acid inhibition. All experiments were done under mesophilic conditions (30 °C) and at pH 7. Methane production was monitored online, using the Automatic Methane Potential Test System. Methane production, soluble chemical oxygen demand and volatile fatty acid content of the samples were measured to calculate the hydrolysis efficiencies. Addition of magnesium, calcium and iron salts clearly mitigated the inhibitory effects of humic acid and hydrolysis efficiencies reached up to 75%, 65% and 72%, respectively, which were similar to control experiments. Conversely, potassium and sodium salts addition did not mitigate the inhibition and hydrolysis efficiencies were found to be less than 40%. Mitigation of humic acid inhibition via salt addition was also validated by inductively coupled plasma atomic emission spectroscopy analyses, which showed the binding capacity of different cations to humic acid. PMID:28955013

The future of methane

DOE Office of Scientific and Technical Information (OSTI.GOV)

Howell, D.G.

1995-12-31

Natural gas, mainly methane, produces lower CO{sub 2}, CO, NO{sub x}, SO{sub 2} and particulate emissions than either oil or coal; thus further substitutions of methane for these fuels could help mitigate air pollution. Methane is, however, a potent greenhouse gas and the domestication of ruminants, cultivation of rice, mining of coal, drilling for oil, and transportation of natural gas have all contributed to a doubling of the amount of atmospheric methane since 1800. Today nearly 300,000 wells yearly produce ca. 21 trillion cubic feet of methane. Known reserves suggest about a 10 year supply at the above rates ofmore » recovery; and the potential for undiscovered resources is obscured by uncertainty involving price, new technologies, and environmental restrictions steming from the need to drill an enormous number of wells, many in ecologically sensitive areas. Until all these aspects of methane are better understood, its future role in the world`s energy mix will remain uncertain. The atomic simplicity of methane, composed of one carbon and four hydrogen atoms, may mask the complexity and importance of this, the most basic of organic molecules. Within the Earth, methane is produced through thermochemical alteration of organic materials, and by biochemical reactions mediated by metabolic processes of archaebacteria; some methane may even be primordial, a residue of planetary accretion. Methane also occurs in smaller volumes in landfills, rice paddies, termite complexes, ruminants, and even many humans. As an energy source, its full energy potential is controversial. Methane is touted by some as a viable bridge to future energy systems, fueled by the sun and uranium and carried by electricity and hydrogen.« less

Struvite Precipitation as a Means of Recovering Nutrients and Mitigating Ammonia Toxicity in a Two-Stage Anaerobic Digester Treating Protein-Rich Feedstocks.

PubMed

Wang, Shunli; Hawkins, Gary L; Kiepper, Brian H; Das, Keshav C

2016-08-03

Accumulation of ammonia, measured as total ammonia nitrogen (TAN), a product of protein decomposition in slaughterhouse wastes, inhibits the anaerobic digestion process, reducing digester productivity and leading to failure. Struvite precipitation (SP) is an effective means to remove TAN and enhance the buffering of substrates. Different Mg and P sources were evaluated as reactants in SP in acidogenic digester effluents to reduce its TAN levels. In order to measure impact of TAN removal, a standard biochemical methane potential (BMP) test was conducted to measure methane yield from treatments that had the highest TAN reductions. SP results showed 6 of 9 reagent combinations resulted in greater than 70% TAN removal. The BMP results indicated that SP treatment by adding Mg(OH)₂ and H₃PO₄ resulted in 57.6% nitrogen recovery and 41.7% increase in methane yield relative to the substrate without SP. SP is an effective technology to improve nutrient recovery and methane production from the anaerobic digestion of protein-rich feedstocks.

Global Air Quality and Climate Impacts of Mitigating Short-lived Climate Pollution in China

NASA Astrophysics Data System (ADS)

Harper, K.; Unger, N.; Heyes, C.; Kiesewetter, G.; Klimont, Z.; Schoepp, W.; Wagner, F.

2014-12-01

China is a major emitter of harmful air pollutants, including the short-lived climate pollutants (SLCPs) and their precursors. Implementation of pollution control technologies provides a mechanism for simultaneously protecting human and ecosystem health and achieving near-term climate co-benefits; however, predicting the outcomes of technical and policy interventions is challenging because the SLCPs participate in both climate warming and cooling and share many common emission sources. Here, we present the results of a combined regional integrated assessment and global climate modeling study aimed at quantifying the near-term climate and air quality co-benefits of selective control of Chinese air pollution emissions. Results from IIASA's Greenhouse Gas - Air Pollution Interactions and Synergies (GAINS) integrated assessment model indicate that methane emission reductions make up > 75% of possible CO2-equivalent emission reductions of the SLCPs and their precursors in China in 2030. A multi-pollutant emission reduction scenario incorporating the 2030 Chinese pollution control measures with the highest potential for future climate impact is applied to the NASA ModelE2 - Yale Interactive Terrestrial Biosphere (NASA ModelE2-YIBs) global carbon - chemistry - climate model to assess the regional and long-range impacts of Chinese SLCP mitigation measures. Using model simulations that incorporate dynamic methane emissions and photosynthesis-dependent isoprene emissions, we quantify the impacts of Chinese reductions of the short-lived air pollutants on radiative forcing and on surface ozone and particulate air pollution. Present-day modeled methane mole fractions are evaluated against SCIAMACHY methane columns and NOAA ESRL/GMD surface flask measurements.

Toward the identification of methanogenic archaeal groups as targets of methane mitigation in livestock animalsr

PubMed Central

St-Pierre, Benoit; Cersosimo, Laura M.; Ishaq, Suzanne L.; Wright, André-Denis G.

2015-01-01

In herbivores, enteric methane is a by-product from the digestion of plant biomass by mutualistic gastrointestinal tract (GIT) microbial communities. Methane is a potent greenhouse gas that is not assimilated by the host and is released into the environment where it contributes to climate change. Since enteric methane is exclusively produced by methanogenic archaea, the investigation of mutualistic methanogen communities in the GIT of herbivores has been the subject of ongoing research by a number of research groups. In an effort to uncover trends that would facilitate the development of efficient methane mitigation strategies for livestock species, we have in this review summarized and compared currently available results from published studies on this subject. We also offer our perspectives on the importance of pursuing current research efforts on the sequencing of gut methanogen genomes, as well as investigating their cellular physiology and interactions with other GIT microorganisms. PMID:26284054

Environmental Development Plan (EDP). Enhanced gas recovery, FY 1977

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1978-03-01

This Enhanced Gcs Recovery EDP addresses the environmental impacts of enhanced gas recovery processes in shale and sandstone, methane drainage from coalbeds, and methane recovery from geopressured aquifers. The EDP addresses planning in two basic areas: environmental research and environmental assessment. Environmental research can be categorized as follows: characterization of pollutants from EGR processes; selective application of monitoring and measuring techniques; evaluation of control/mitigation techniques; and evaluation of the synergistic impacts of the development of EGR techniques. Environmental assessment activities scheduled by EDP include: assessment of ecological impacts; assessment of socioeconomic effects; EIA/EIS preparation; evaluation of control technology needs; andmore » analysis of applicable and proposed emission, effluent, and health and safety standards. The EGR EDP includes an EGR technology overview (Section 2), a discussion of EGR environmental issues and requirements (Section 3), an environmental action plan (Section 4), an environmental management strategy for the EGR program (Section 5), and supporting appendices which present information on Federal legislation applicable to EGR technology, a summary of ongoing and completed research, and future research and assessment projects.« less

Evaluation of Genetic Variation in Rice to Mitigate Methane Emissions

USDA-ARS?s Scientific Manuscript database

Agriculture is recognized as a significant contributor to greenhouse gas emissions (GHGE) globally. Paddy rice is a significant source of methane emissions. Methane accounts for about 11% of all U.S. GHGE and it is ~25 times more potent in global warming potential than carbon dioxide. Research has s...

Future methane emissions from the heavy-duty natural gas transportation sector for stasis, high, medium, and low scenarios in 2035.

PubMed

Clark, Nigel N; Johnson, Derek R; McKain, David L; Wayne, W Scott; Li, Hailin; Rudek, Joseph; Mongold, Ronald A; Sandoval, Cesar; Covington, April N; Hailer, John T

2017-12-01

Today's heavy-duty natural gas-fueled fleet is estimated to represent less than 2% of the total fleet. However, over the next couple of decades, predictions are that the percentage could grow to represent as much as 50%. Although fueling switching to natural gas could provide a climate benefit relative to diesel fuel, the potential for emissions of methane (a potent greenhouse gas) from natural gas-fueled vehicles has been identified as a concern. Since today's heavy-duty natural gas-fueled fleet penetration is low, today's total fleet-wide emissions will be also be low regardless of per vehicle emissions. However, predicted growth could result in a significant quantity of methane emissions. To evaluate this potential and identify effective options for minimizing emissions, future growth scenarios of heavy-duty natural gas-fueled vehicles, and compressed natural gas and liquefied natural gas fueling stations that serve them, have been developed for 2035, when the populations could be significant. The scenarios rely on the most recent measurement campaign of the latest manufactured technology, equipment, and vehicles reported in a companion paper as well as projections of technology and practice advances. These "pump-to-wheels"(PTW) projections do not include methane emissions outside of the bounds of the vehicles and fuel stations themselves and should not be confused with a complete wells-to-wheels analysis. Stasis, high, medium, and low scenario PTW emissions projections for 2035 were 1.32%, 0.67%, 0.33%, and 0.15% of the fuel used. The scenarios highlight that a large emissions reductions could be realized with closed crankcase operation, improved best practices, and implementation of vent mitigation technologies. Recognition of the potential pathways for emissions reductions could further enhance the heavy-duty transportation sectors ability to reduce carbon emissions. Newly collected pump-to-wheels methane emissions data for current natural gas technologies were combined with future market growth scenarios, estimated technology advancements, and best practices to examine the climate benefit of future fuel switching. The analysis indicates the necessary targets of efficiency, methane emissions, market penetration, and best practices necessary to enable a pathway for natural gas to reduce the carbon intensity of the heavy-duty transportation sector.

The future of energy gases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Howell, D.G.

1995-04-01

Natural gas, mainly methane, produces lower CO {sub 2}, CO, NO{sub x}, SO {sub 2} and particulate emissions than either oil or coal; thus further substitutions of methane for these fuels could help mitigate air pollution. Methane is, however, a potent greenhouse gas and the domestication of ruminants, cultivation of rice, mining of coal, drilling for oil, and transportation of natural gas have all contributed to a doubling of the amount of atmospheric methane since 1800. Today nearly 300,000 wells yearly produce each 21 trillion cubic feet of methane. Known reserves suggest about a 10 year supply at the abovemore » rates of recovery; and the potential for undiscovered resources is obscured by uncertainty involving price, new technologies, and environmental restrictions stemming from the need to drill an enormous number of wells, many in ecologically sensitive areas. The atomic simplicity of methane, composed of one carbon and four hydrogen atoms, may mask the complexity of this, the most basic of organic molecules. Within the Earth, methane is produced through thermochemical alteration of organic materials, and by biochemical reactions mediated by metabolic processes of archaebacteria; some methane may even be primordial, a residue of planetary accretion. Methane is known to exist in the mantle and lower crust. Near the Earth`s surface, methane occurs in enormous oil and/or gas reservoirs in rock, and is absorbed in coal, dissolved in water, and trapped in a latticework of ice-like material called gas hydrate. Methane also occurs in smaller volumes in landfills, rice paddies, termite complexes, ruminants, and even many humans. As an energy source, methane accounts for roughly 25 percent of current U.S. consumption, but its full energy potential is controversial. Methane is touted by some as a viable bridge to future energy systems, fueled by the sun and uranium and carried by electricity and hydrogen.« less

Vehicle emissions of short-lived and long-lived climate forcers: trends and tradeoffs.

PubMed

Edwards, Morgan R; Klemun, Magdalena M; Kim, Hyung Chul; Wallington, Timothy J; Winkler, Sandra L; Tamor, Michael A; Trancik, Jessika E

2017-08-24

Evaluating technology options to mitigate the climate impacts of road transportation can be challenging, particularly when they involve a tradeoff between long-lived emissions (e.g., carbon dioxide) and short-lived emissions (e.g., methane or black carbon). Here we present trends in short- and long-lived emissions for light- and heavy-duty transport globally and in the U.S., EU, and China over the period 2000-2030, and we discuss past and future changes to vehicle technologies to reduce these emissions. We model the tradeoffs between short- and long-lived emission reductions across a range of technology options, life cycle emission intensities, and equivalency metrics. While short-lived vehicle emissions have decreased globally over the past two decades, significant reductions in CO 2 will be required by mid-century to meet climate change mitigation targets. This is true regardless of the time horizon used to compare long- and short-lived emissions. The short-lived emission intensities of some low-CO 2 technologies are higher than others, and thus their suitability for meeting climate targets depends sensitively on the evaluation time horizon. Other technologies offer low intensities of both short-lived emissions and CO 2 .

Investigating options for attenuating methane emission from Indian rice fields.

PubMed

Singh, S N; Verma, Amitosh; Tyagi, Larisha

2003-08-01

The development of methods and strategies to reduce the emission of methane from paddy fields is a central component of ongoing efforts to protect the Earth's atmosphere and to avert a possible climate change. It appears from this investigation that there can be more than one strategy to contain methane emission from paddy fields, which are thought to be a major source of methane emission in tropical Asia. Promising among the mitigating options may be water management, organic amendments, fertilizer application and selection of rice cultivars. It is always better to adopt multi-pronged strategies to contain CH4 efflux from rice wetlands. Use of fermented manures with low C/N ratio, application of sulfate-containing chemical fertilizers, selection of low CH4 emitting rice cultivars, and implementation of one or two short aeration periods before the heading stage can be effective options to minimize CH4 emission from paddy fields. Among these strategies, water management, which appears to be the best cost-effective and eco-friendly way for methane mitigation, is only possible when excess water is available for reflooding after short soil drying at the right timing and stage. However, in tropical Asia, rice fields are naturally flooded during the monsoonal rainy season and fully controlled drainage is often impossible. In such situation, water deficits during the vegetative and reproductive stage may drastically affect the rice yields. Thus, care must be taken to mitigate methane emission without affecting rice yields.

Increased importance of methane reduction for a 1.5 degree target

NASA Astrophysics Data System (ADS)

Collins, William J.; Webber, Christopher P.; Cox, Peter M.; Huntingford, Chris; Lowe, Jason; Sitch, Stephen; Chadburn, Sarah E.; Comyn-Platt, Edward; Harper, Anna B.; Hayman, Garry; Powell, Tom

2018-04-01

To understand the importance of methane on the levels of carbon emission reductions required to achieve temperature goals, a processed-based approach is necessary rather than reliance on the transient climate response to emissions. We show that plausible levels of methane (CH4) mitigation can make a substantial difference to the feasibility of achieving the Paris climate targets through increasing the allowable carbon emissions. This benefit is enhanced by the indirect effects of CH4 on ozone (O3). Here the differing effects of CH4 and CO2 on land carbon storage, including the effects of surface O3, lead to an additional increase in the allowable carbon emissions with CH4 mitigation. We find a simple robust relationship between the change in the 2100 CH4 concentration and the extra allowable cumulative carbon emissions between now and 2100 (0.27 ± 0.05 GtC per ppb CH4). This relationship is independent of modelled climate sensitivity and precise temperature target, although later mitigation of CH4 reduces its value and thus methane reduction effectiveness. Up to 12% of this increase in allowable emissions is due to the effect of surface ozone. We conclude early mitigation of CH4 emissions would significantly increase the feasibility of stabilising global warming below 1.5 °C, alongside having co-benefits for human and ecosystem health.

Coal-Packed Methane Biofilter for Mitigation of Green House Gas Emissions from Coal Mine Ventilation Air

PubMed Central

Limbri, Hendy; Gunawan, Cindy; Thomas, Torsten; Smith, Andrew; Scott, Jason; Rosche, Bettina

2014-01-01

Methane emitted by coal mine ventilation air (MVA) is a significant greenhouse gas. A mitigation strategy is the oxidation of methane to carbon dioxide, which is approximately twenty-one times less effective at global warming than methane on a mass-basis. The low non-combustible methane concentrations at high MVA flow rates call for a catalytic strategy of oxidation. A laboratory-scale coal-packed biofilter was designed and partially removed methane from humidified air at flow rates between 0.2 and 2.4 L min−1 at 30°C with nutrient solution added every three days. Methane oxidation was catalysed by a complex community of naturally-occurring microorganisms, with the most abundant member being identified by 16S rRNA gene sequence as belonging to the methanotrophic genus Methylocystis. Additional inoculation with a laboratory-grown culture of Methylosinus sporium, as investigated in a parallel run, only enhanced methane consumption during the initial 12 weeks. The greatest level of methane removal of 27.2±0.66 g methane m−3 empty bed h−1 was attained for the non-inoculated system, which was equivalent to removing 19.7±2.9% methane from an inlet concentration of 1% v/v at an inlet gas flow rate of 1.6 L min−1 (2.4 min empty bed residence time). These results show that low-cost coal packing holds promising potential as a suitable growth surface and contains methanotrophic microorganisms for the catalytic oxidative removal of methane. PMID:24743729

Expression of barley SUSIBA2 transcription factor yields high-starch low-methane rice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Su, J.; Hu, C.; Yan, X.

Atmospheric methane is the second most important greenhouse gas after carbon dioxide, and is responsible for about 20% of the global warming effect since pre-industrial times. Rice paddies are the largest anthropogenic methane source and produce 7–17% of atmospheric methane. Warm waterlogged soil and exuded nutrients from rice roots provide ideal conditions for methanogenesis in paddies with annual methane emissions of 25–100-million tonnes. This scenario will be exacerbated by an expansion in rice cultivation needed to meet the escalating demand for food in the coming decades4. There is an urgent need to establish sustainable technologies for increasing rice production whilemore » reducing methane fluxes from rice paddies. However, ongoing efforts for methane mitigation in rice paddies are mainly based on farming practices and measures that are difficult to implement5. Despite proposed strategies to increase rice productivity and reduce methane emissions4,6, no high-starch low-methane-emission rice has been developed. Here we show that the addition of a single transcription factor gene, barley SUSIBA2, conferred a shift of carbon flux to SUSIBA2 rice, favouring the allocation of photosynthates to aboveground biomass over allocation to roots. The altered allocation resulted in an increased biomass and starch content in the seeds and stems, and suppressed methanogenesis, possibly through a reduction in root exudates. Three-year field trials in China demonstrated that the cultivation of SUSIBA2 rice was associated with a significant reduction in methane emissions and a decrease in rhizospheric methanogen levels. SUSIBA2 rice offers a sustainable means of providing increased starch content for food production while reducing greenhouse gas emissions from rice cultivation. Approaches to increase rice productivity and reduce methane emissions as seen in SUSIBA2 rice may be particularly beneficial in a future climate with rising temperatures resulting in increased methane emissions from paddies.« less

Quantifying Fugitive Methane Emissions at an Underground Coal Fire Using Cavity Ring-Down Spectroscopy Technology

NASA Astrophysics Data System (ADS)

Fleck, D.; Gannon, L.; Kim-Hak, D.; Ide, T.

2016-12-01

Understanding methane emissions is of utmost importance due to its greenhouse warming potential. Methane emissions can occur from a variety of natural and anthropogenic sources which include wetlands, landfills, oil/gas/coal extraction activities, underground coal fires, and natural gas distribution systems. Locating and containing these emissions are critical to minimizing their environmental impacts and economically beneficial when retrieving large fugitive amounts. In order to design a way to mitigate these methane emissions, they must first be accurately quantified. One such quantification method is to measure methane fluxes, which is a measurement technique that is calculated based on rate of gas accumulation in a known chamber volume over methane seepages. This allows for quantification of greenhouse gas emissions at a localized level (sub one meter) that can complement remote sensing and other largescale modeling techniques to further paint the picture of emission points. High performance analyzers are required to provide both sufficient temporal resolution and precise concentration measurements in order to make these measurements over only minutes. A method of measuring methane fluxes was developed using the latest portable, battery-powered Cavity Ring-Down Spectroscopy analyzer from Picarro (G4301). In combination with a mobile accumulation chamber, the instrument allows for rapid measurement of methane and carbon dioxide fluxes over wide areas. For this study, methane fluxes that were measured at an underground coal fire near the Four Corners region using the Picarro analyzer are presented. The flux rates collected demonstrate the ability for the analyzer to detect methane fluxes across many orders of magnitude. Measurements were accompanied by simultaneously geotagging the measurements with GPS to georeferenced the data. Methane flux data were instrumental in our ability to characterize the extent and the migration of the underground fire. In the future, examining the tradeoffs and dynamics between methane and carbon dioxide emissions will allow us to further understand the propagation and evolution of these large greenhouse gas emitters.

Expression of barley SUSIBA2 transcription factor yields high-starch low-methane rice

NASA Astrophysics Data System (ADS)

Su, J.; Hu, C.; Yan, X.; Jin, Y.; Chen, Z.; Guan, Q.; Wang, Y.; Zhong, D.; Jansson, C.; Wang, F.; Schnürer, A.; Sun, C.

2015-07-01

Atmospheric methane is the second most important greenhouse gas after carbon dioxide, and is responsible for about 20% of the global warming effect since pre-industrial times. Rice paddies are the largest anthropogenic methane source and produce 7-17% of atmospheric methane. Warm waterlogged soil and exuded nutrients from rice roots provide ideal conditions for methanogenesis in paddies with annual methane emissions of 25-100-million tonnes. This scenario will be exacerbated by an expansion in rice cultivation needed to meet the escalating demand for food in the coming decades. There is an urgent need to establish sustainable technologies for increasing rice production while reducing methane fluxes from rice paddies. However, ongoing efforts for methane mitigation in rice paddies are mainly based on farming practices and measures that are difficult to implement. Despite proposed strategies to increase rice productivity and reduce methane emissions, no high-starch low-methane-emission rice has been developed. Here we show that the addition of a single transcription factor gene, barley SUSIBA2 (refs 7, 8), conferred a shift of carbon flux to SUSIBA2 rice, favouring the allocation of photosynthates to aboveground biomass over allocation to roots. The altered allocation resulted in an increased biomass and starch content in the seeds and stems, and suppressed methanogenesis, possibly through a reduction in root exudates. Three-year field trials in China demonstrated that the cultivation of SUSIBA2 rice was associated with a significant reduction in methane emissions and a decrease in rhizospheric methanogen levels. SUSIBA2 rice offers a sustainable means of providing increased starch content for food production while reducing greenhouse gas emissions from rice cultivation. Approaches to increase rice productivity and reduce methane emissions as seen in SUSIBA2 rice may be particularly beneficial in a future climate with rising temperatures resulting in increased methane emissions from paddies.

A comprehensive review on food waste anaerobic digestion: Research updates and tendencies.

PubMed

Ren, Yuanyuan; Yu, Miao; Wu, Chuanfu; Wang, Qunhui; Gao, Ming; Huang, Qiqi; Liu, Yu

2018-01-01

Anaerobic digestion has been practically applied in agricultural and industrial waste treatment and recognized as an economical-effective way for food waste disposal. This paper presented an overview on the researches about anaerobic digestion of food waste. Technologies (e.g., pretreatment, co-digestion, inhibition and mitigation, anaerobic digestion systems, etc.) were introduced and evaluated on the basis of bibliometric analysis. Results indicated that ethanol and aerobic prefermentation were novel approaches to enhance substrates hydrolysis and methane yield. With the promotion of resource recovery, more attention should be paid to biorefinery technologies which can produce more useful products toward zero emissions. Furthermore, a technological route for food waste conversion based on anaerobic digestion was proposed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Metal Hydrides, MOFs, and Carbon Composites as Space Radiation Shielding Mitigators

NASA Technical Reports Server (NTRS)

Atwell, William; Rojdev, Kristina; Liang, Daniel; Hill, Matthew

2014-01-01

Recently, metal hydrides and MOFs (Metal-Organic Framework/microporous organic polymer composites - for their hydrogen and methane storage capabilities) have been studied with applications in fuel cell technology. We have investigated a dual-use of these materials and carbon composites (CNT-HDPE) to include space radiation shielding mitigation. In this paper we present the results of a detailed study where we have analyzed 64 materials. We used the Band fit spectra for the combined 19-24 October 1989 solar proton events as the input source term radiation environment. These computational analyses were performed with the NASA high energy particle transport/dose code HZETRN. Through this analysis we have identified several of the materials that have excellent radiation shielding properties and the details of this analysis will be discussed further in the paper.

Emissions from Residential Combustion considering End-Uses and Spatial Constraints

NASA Astrophysics Data System (ADS)

Bond, T. C.; Lam, N. L.; Winijkul, E.

2015-12-01

Cooking, heating, and other activities in the residential sector are major sources of indoor and outdoor air pollution, especially when solid fuels provide energy. Because of these deleterious effects, multinational strategies to alter technology and reduce emissions have been proposed, but to date, they have ignored many constraints on feasibility. We describe a framework to apportion national energy consumption among land types and household end-uses, to calculate emissions, and to evaluate mitigation strategies. We provide year-2010 emissions of particulate matter, black carbon, organic carbon, nitrogen oxides, methane, non-methane hydrocarbons, carbon monoxide, and carbon dioxide. The study area includes regions where solid biomass fuel provides more than 50% of total residential energy: Latin America, Africa, and Asia. Using nightlight data and population density, we classify land types as urban, electrified rural with and without forest access, and non-electrified rural with and without forest access. We apportion national-level residential fuel consumption among land types and end-uses, and assign technologies to each combination. About 13% of energy is consumed in urban areas, and 45% in non-urban land near forests. About half the energy is consumed in land without access to electricity. Cooking accounts for 54% of consumption, heating 9%, and lighting only 2%, with unidentified uses making up the remainder. We examine possible policies, considering realistic factors that constrain mitigation. Scenarios explored are: (1) cleanest current stove, where plausible existing technology is deployed; (2) stove standards, where stoves are designed to meet performance standards; and (3) clean fuels, where users adopt the cleanest plausible fuels; we assume that people living in forest access areas continue to use wood. For cleaner stoves, emission reductions range from 25-82%, depending on the pollutant. The clean-fuels scenario reduces emissions by 18-25%.

Intermittent micro-aeration control of methane emissions from an integrated vertical-flow constructed wetland during agricultural domestic wastewater treatment.

PubMed

Liu, Xiaoling; Zhang, Ke; Fan, Liangqian; Luo, Hongbing; Jiang, Mingshu; Anderson, Bruce C; Li, Mei; Huang, Bo; Yu, Lijuan; He, Guozhu; Wang, Jingting; Pu, Aiping

2018-06-16

It is very important to control methane emissions to mitigate global warming. An intermittent micro-aeration control system was used to control methane emissions from an integrated vertical-flow constructed wetland (IVCW) to treat agricultural domestic wastewater pollution in this study. The optimized intermittent micro-aeration conditions were a 20-min aeration time and 340-min non-aeration time, 3.9 m 3  h -1 aeration intensity, evenly distributed micro-aeration diffusers at the tank bottom, and an aeration period of every 6 h. Methane flux emission by intermittent micro-aeration was decreased by 60.7% under the optimized conditions. The average oxygen transfer efficiency was 26.73%. The control of CH 4 emission from IVCWs was most strongly influenced by the intermittent micro-aeration diffuser distribution, followed by aeration intensity, aeration time, and water depth. Scaling up of IVCWs is feasible in rural areas by using intermittent micro-aeration control as a mitigation measure for methane gas emissions for climate change.

Copper enhances the activity and salt resistance of mixed methane-oxidizing communities.

PubMed

van der Ha, David; Hoefman, Sven; Boeckx, Pascal; Verstraete, Willy; Boon, Nico

2010-08-01

Effluents of anaerobic digesters are an underestimated source of greenhouse gases, as they are often saturated with methane. A post-treatment with methane-oxidizing bacterial consortia could mitigate diffuse emissions at such sites. Semi-continuously fed stirred reactors were used as model systems to characterize the influence of the key parameters on the activity of these mixed methanotrophic communities. The addition of 140 mg L(-1) NH (4) (+) -N had no significant influence on the activity nor did a temperature increase from 28 degrees C to 35 degrees C. On the other hand, addition of 0.64 mg L(-1) of copper(II) increased the methane removal rate by a factor of 1.5 to 1.7 since the activity of particulate methane monooxygenase was enhanced. The influence of different concentrations of NaCl was also tested, as effluents of anaerobic digesters often contain salt levels up to 10 g NaCl L(-1). At a concentration of 11 g NaCl L(-1), almost no methane-oxidizing activity was observed in the reactors without copper addition. Yet, reactors with copper addition exhibited a sustained activity in the presence of NaCl. A colorimetric test based on naphthalene oxidation showed that soluble methane monooxygenase was inhibited by copper, suggesting that the particulate methane monooxygenase was the active enzyme and thus more salt resistant. The results obtained demonstrate that the treatment of methane-saturated effluents, even those with increased ammonium (up to 140 mg L(-1) NH (4) (+) -N) and salt levels, can be mitigated by implementation of methane-oxidizing microbial consortia.

CO{sub 2} Reuse in Petrochemical Facilities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jason Trembly; Brian Turk; Maruthi Pavani

2010-12-31

To address public concerns regarding the consequences of climate change from anthropogenic carbon dioxide (CO{sub 2}) emissions, the U.S. Department of Energy's National Energy Technology Laboratory (DOE/NETL) is actively funding a CO{sub 2} management program to develop technologies capable of mitigating CO{sub 2} emissions from power plant and industrial facilities. Over the past decade, this program has focused on reducing the costs of carbon capture and storage technologies. Recently, DOE/NETL launched an alternative CO{sub 2} mitigation program focused on beneficial CO{sub 2} reuse to support the development of technologies that mitigate emissions by converting CO{sub 2} into valuable chemicals andmore » fuels. RTI, with DOE/NETL support, has been developing an innovative beneficial CO{sub 2} reuse process for converting CO{sub 2} into substitute natural gas (SNG) by using by-product hydrogen (H{sub 2)-containing fuel gas from petrochemical facilities. This process leveraged commercial reactor technology currently used in fluid catalytic crackers in petroleum refining and a novel nickel (Ni)-based catalyst developed by RTI. The goal was to generate an SNG product that meets the pipeline specifications for natural gas, making the SNG product completely compatible with the existing natural gas infrastructure. RTI's technology development efforts focused on demonstrating the technical feasibility of this novel CO{sub 2} reuse process and obtaining the necessary engineering information to design a pilot demonstration unit for converting about 4 tons per day (tons/day) of CO{sub 2} into SNG at a suitable host site. This final report describes the results of the Phase I catalyst and process development efforts. The methanation activity of several commercial fixed-bed catalysts was evaluated under fluidized-bed conditions in a bench-scale reactor to identify catalyst performance targets. RTI developed two fluidizable Ni-based catalyst formulations (Cat-1 and Cat-3) that demonstrated equal or better performance than that of commercial methanation catalysts. The Cat-1 and Cat-3 formulations were successfully scaled up using commercial manufacturing equipment at the Sud-Chemie Inc. pilot-plant facility in Louisville, KY. Pilot transport reactor testing with RTI's Cat-1 formulation at Kellog Brown & Root's Technology Center demonstrated the ability of the process to achieve high single-pass CO{sub 2} conversion. Using information acquired from bench- and pilot-scale testing, a basic engineering design package was prepared for a 4-ton/day CO{sub 2} pilot demonstration unit, including process and instrumentation diagrams, equipment list, control philosophy, and preliminary cost estimate.« less

Characterization and biodegradability of sludge from a high rate A-stage contact tank and B-stage membrane bioreactor of a pilot-scale AB system treating municipal wastewaters.

PubMed

Trzcinski, Antoine Prandota; Ganda, Lily; Kunacheva, Chinagarn; Zhang, Dong Qing; Lin, Li Leonard; Tao, Guihe; Lee, Yingjie; Ng, Wun Jern

2016-10-01

In light of global warming mitigation efforts, increasing sludge disposal costs, and need for reduction in the carbon footprint of wastewater treatment plants, innovation in treatment technology has been tailored towards energy self-sufficiency. The AB process is a promising technology for achieving maximal energy recovery from wastewaters with minimum energy expenditure and therefore inherently reducing excess sludge production. Characterization of this novel sludge and its comparison with the more conventional B-stage sludge are necessary for a deeper understanding of AB treatment process design. This paper presents a case study of a pilot-scale AB system treating municipal wastewaters as well as a bio- (biochemical methane potential and adenosine tri-phosphate analysis) and physico-chemical properties (chemical oxygen demand, sludge volume index, dewaterability, calorific value, zeta potential and particle size distribution) comparison of the organic-rich A-stage against the B-stage activated sludge. Compared to the B-sludge, the A-sludge yielded 1.4 to 4.9 times more methane throughout the 62-week operation.

Designing and implementing science-based methane policies

NASA Astrophysics Data System (ADS)

George, F.

2017-12-01

The phenomenal growth in shale gas production across the U.S. has significantly improved the energy security and economic prospects of the country. Natural gas is a "versatile" fuel that has application in every major end-use sector of the economy, both as a fuel and a feedstock. Natural gas has also played a significant role in reducing CO2 emissions from the power sector by displacing more carbon intensive fossil fuels. However, emissions of natural gas (predominantly methane) from the wellhead to the burner tip can erode this environmental benefit. Preserving the many benefits of America's natural gas resources requires smart, science-based policies to optimize the energy delivery efficiency of the natural gas supply chain and ensure that natural gas remains a key pillar in our transition to a low-carbon economy. Southwestern Energy (SWN) is the third largest natural gas producer in the United States. Over the last several years, SWN has participated in a number of scientific studies with regulatory agencies, academia and non-governmental entities that have led to over a dozen peer-reviewed papers on methane emissions from oil and gas operations. This presentation will review how our participation in these studies has informed our internal policies and procedures, as well as our external programs, including the ONE Future coalition (ONE Future). In particular, the presentation will highlight the impact of such studies on our Leak Detection and Repair (LDAR) program, designing new methane research and on the ONE Future initiatives - all with the focus of improving the delivery efficiency of oil and gas operations. Our experience supports continued research in the detection and mitigation of methane emissions, with emphasis on longer duration characterization of methane emissions from oil and gas facilities and further development of cost-effective methane detection and mitigation techniques. We conclude from our scientific and operational experiences that a performance-based methane mitigation policy like the ONE Future will lead to more operationally efficient and cost-effective reductions in methane emissions from the natural gas supply chain.

Representative concentration pathways and mitigation scenarios for nitrous oxide

NASA Astrophysics Data System (ADS)

Davidson, Eric A.

2012-06-01

The challenges of mitigating nitrous oxide (N2O) emissions are substantially different from those for carbon dioxide (CO2) and methane (CH4), because nitrogen (N) is essential for food production, and over 80% of anthropogenic N2O emissions are from the agricultural sector. Here I use a model of emission factors of N2O to demonstrate the magnitude of improvements in agriculture and industrial sectors and changes in dietary habits that would be necessary to match the four representative concentration pathways (RCPs) now being considered in the fifth assessment report (AR5) of the Intergovernmental Panel on Climate Change (IPCC). Stabilizing atmospheric N2O by 2050, consistent with the most aggressive of the RCP mitigation scenarios, would require about 50% reductions in emission factors in all sectors and about a 50% reduction in mean per capita meat consumption in the developed world. Technologies exist to achieve such improved efficiencies, but overcoming social, economic, and political impediments for their adoption and for changes in dietary habits will present large challenges.

Mapping suitability of rice production systems for mitigation: Strategic approach for prioritizing improved irrigation management across scales

NASA Astrophysics Data System (ADS)

Wassmann, Reiner; Sander, Bjoern Ole

2016-04-01

After the successful conclusion of the COP21 in Paris, many developing countries are now embracing the task of reducing emissions with much vigor than previously. In many countries of South and South-East Asia, the agriculture sector constitutes a vast share of the national GHG budget which can mainly be attributed to methane emissions from flooded rice production. Thus, rice growing countries are now looking for tangible and easily accessible information as to how to reduce emissions from rice production in an efficient manner. Given present and future food demand, mitigation options will have to comply with aim of increasing productivity. At the same time, limited financial resources demand for strategic planning of potential mitigation projects based on cost-benefit ratios. At this point, the most promising approach for mitigating methane emissions from rice is an irrigation technique called Alternate Wetting and Drying (AWD). AWD was initially developed for saving water and subsequently, represents an adaptation strategy in its own right by coping with less rainfall. Moreover, AWD also reduces methane emissions in a range from 30-70%. However, AWD is not universally suitable. It is attractive to farmers who have to pump water and may save fuel under AWD, but renders limited incentives in situations where there is no real pressing water scarcity. Thus, planning for AWD adoption at larger scale, e.g. for country-wide programs, should be based on a systematic prioritization of target environments. This presentation encompasses a new methodology for mapping suitability of water-saving in rice production - as a means for planning adaptation and mitigation programs - alongside with preliminary results. The latter comprises three new GIS maps on climate-driven suitability of AWD in major rice growing countries (Philippines, Vietnam, Bangladesh). These maps have been derived from high-resolution data of the areal and temporal extent of rice production that are now available for most Asian countries. These GIS maps have been expanded by adding relevant data on climate and soil texture to assess the water balance at any given point (in space and time). In the next step, these water balances (available in 10d intervals) have been integrated over the entire season to determine the climate-driven suitability for AWD implementation. These new GIS maps are vital for policy makers and other stakeholders who are now faced with the challenge of developing mitigation programs. The GIS data bases could further be expanded by more GIS layers on irrigation specific information (e.g. use of pumps) as well as on other mitigation approaches such as improved post-harvest technologies for preventing straw burning.

Propulsion and Cryogenics Advanced Development (PCAD) Project Propulsion Technologies for the Lunar Lander

NASA Technical Reports Server (NTRS)

Klem, Mark D.; Smith, Timothy D.

2008-01-01

The Propulsion and Cryogenics Advanced Development (PCAD) Project in the Exploration Technology Development Program is developing technologies as risk mitigation for Orion and the Lunar Lander. An integrated main and reaction control propulsion system has been identified as a candidate for the Lunar Lander Ascent Module. The propellants used in this integrated system are Liquid Oxygen (LOX)/Liquid Methane (LCH4) propellants. A deep throttle pump fed Liquid Oxygen (LOX)/Liquid Hydrogen (LH2) engine system has been identified for the Lunar Lander Descent Vehicle. The propellant combination and architecture of these propulsion systems are novel and would require risk reduction prior to detailed design and development. The PCAD Project addresses the technology requirements to obtain relevant and necessary test data to further the technology maturity of propulsion hardware utilizing these propellants. This plan and achievements to date will be presented.

Modeling the trade-off between diet costs and methane emissions: A goal programming approach.

PubMed

Moraes, L E; Fadel, J G; Castillo, A R; Casper, D P; Tricarico, J M; Kebreab, E

2015-08-01

Enteric methane emission is a major greenhouse gas from livestock production systems worldwide. Dietary manipulation may be an effective emission-reduction tool; however, the associated costs may preclude its use as a mitigation strategy. Several studies have identified dietary manipulation strategies for the mitigation of emissions, but studies examining the costs of reducing methane by manipulating diets are scarce. Furthermore, the trade-off between increase in dietary costs and reduction in methane emissions has only been determined for a limited number of production scenarios. The objective of this study was to develop an optimization framework for the joint minimization of dietary costs and methane emissions based on the identification of a set of feasible solutions for various levels of trade-off between emissions and costs. Such a set of solutions was created by the specification of a systematic grid of goal programming weights, enabling the decision maker to choose the solution that achieves the desired trade-off level. Moreover, the model enables the calculation of emission-mitigation costs imputing a trading value for methane emissions. Emission imputed costs can be used in emission-unit trading schemes, such as cap-and-trade policy designs. An application of the model using data from lactating cows from dairies in the California Central Valley is presented to illustrate the use of model-generated results in the identification of optimal diets when reducing emissions. The optimization framework is flexible and can be adapted to jointly minimize diet costs and other potential environmental impacts (e.g., nitrogen excretion). It is also flexible so that dietary costs, feed nutrient composition, and animal nutrient requirements can be altered to accommodate various production systems. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Role of Biochar in Mitigation of Climate Change

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lehmann, Johannes C.; Amonette, James E.; Roberts, Kelli G.

2010-09-30

By virtue of the large fraction of the terrestrial carbon (C) cycle controlled by human activities, agroecosystems are both sources and sinks for greenhouse gases. Their potential role in mitigation of climate change thus depends on a dual strategy of decreasing greenhouse gas emissions while increasing sinks so that the net impact on climate warming is less than at present. Emissions of carbon dioxide, methane and nitrous oxide arise from various agricultural activities, ranging from land clearing to ploughing, fertilization, and animal husbandry. Reductions in these emissions can be achieved by decreasing the heterotrophic conversion of organic C to carbonmore » dioxide, and by better management of agricultural waste streams to minimize release of methane and nitrous oxide. Current sinks include C stored in standing biomass and soil organic matter, and the oxidation of atmospheric methane by soil bacteria. These sinks can be enhanced by increasing net primary productivity, thereby actively withdrawing more carbon dioxide from the atmosphere, and by promoting more oxidation of methane by soils. Judicious biochar management may contribute to both strategies, reductions of emissions by agriculture and active withdrawal of atmospheric carbon dioxide, as part of a comprehensive scheme in agricultural and forestry watersheds. Biochar is a carbon-rich organic material generated by heating biomass in the absence, or under a limited supply, of oxygen. This so-called charring or pyrolysis process has been used to produce charcoal as a source of fuel for millennia. Recently, interest has grown in understanding the potential of this process to improve soil health by adding biochar as an amendment to soil, to manage agricultural and forestry wastes, to generate energy, to decrease net emissions of nitrous oxide and methane, and to store carbon (C). The main incentive of biochar systems for mitigation of climate change is to increase the stability of organic matter or biomass. This stability is achieved by the conversion of fresh organic materials, which mineralize comparatively quickly, into biochar, which mineralizes much more slowly. The difference between the mineralization of uncharred and charred material results in a greater amount of carbon storage in soils and a lower amount of carbon dioxide, the major greenhouse gas, in the atmosphere. The principle of creating and managing biochar systems may address multiple environmental constraints. Biochar may help not only in mitigating climate change, but also fulfill a role in management of agricultural and forestry wastes, enhancement of soil sustainability, and generation of energy. Pyrolysis is a comparatively low-technology intervention. Deployment on a global scale, however, must be done carefully if the full mitigation potential is to be reached. Critical aspects of a successful implementation are that: 1) the biochar is sufficiently stable to reduce greenhouse gases in the atmosphere for an appropriate length of time. 2) the storage of carbon as biochar in soil is not offset by greenhouse gas emissions along the value chain of the system, such as mineralization of soil carbon or emissions of other greenhouse gases (e.g., methane and nitrous oxide). 3) net emission reductions are achieved for the entire life cycle of the system including indirect land use. 4) the biochar product does not cause unwanted side effects in soil. 5) the handling and production of biochar are in compliance with health and safety standards and do not pose hurdles to implementation. and 6) the biochar system is financially viable. This chapter discusses these issues in separate sections, identifies knowledge gaps, and proposes a road map to fully evaluate an environmentally and socially safe exploration of the biochar potential to mitigate climate change if adopted widely around the world.« less

Simultaneously Mitigating Near-Term Climate Change and Improving Human Health and Food Security

NASA Astrophysics Data System (ADS)

Shindell, Drew; Kuylenstierna, Johan C. I.; Vignati, Elisabetta; van Dingenen, Rita; Amann, Markus; Klimont, Zbigniew; Anenberg, Susan C.; Muller, Nicholas; Janssens-Maenhout, Greet; Raes, Frank; Schwartz, Joel; Faluvegi, Greg; Pozzoli, Luca; Kupiainen, Kaarle; Höglund-Isaksson, Lena; Emberson, Lisa; Streets, David; Ramanathan, V.; Hicks, Kevin; Oanh, N. T. Kim; Milly, George; Williams, Martin; Demkine, Volodymyr; Fowler, David

2012-01-01

Tropospheric ozone and black carbon (BC) contribute to both degraded air quality and global warming. We considered ~400 emission control measures to reduce these pollutants by using current technology and experience. We identified 14 measures targeting methane and BC emissions that reduce projected global mean warming ~0.5°C by 2050. This strategy avoids 0.7 to 4.7 million annual premature deaths from outdoor air pollution and increases annual crop yields by 30 to 135 million metric tons due to ozone reductions in 2030 and beyond. Benefits of methane emissions reductions are valued at $700 to $5000 per metric ton, which is well above typical marginal abatement costs (less than $250). The selected controls target different sources and influence climate on shorter time scales than those of carbon dioxide-reduction measures. Implementing both substantially reduces the risks of crossing the 2°C threshold.

Advanced Plasma Pyrolysis Assembly (PPA) Reactor and Process Development

NASA Technical Reports Server (NTRS)

Wheeler, Richard R., Jr.; Hadley, Neal M.; Dahl, Roger W.; Abney, Morgan B.; Greenwood, Zachary; Miller, Lee; Medlen, Amber

2012-01-01

Design and development of a second generation Plasma Pyrolysis Assembly (PPA) reactor is currently underway as part of NASA's Atmosphere Revitalization Resource Recovery effort. By recovering up to 75% of the hydrogen currently lost as methane in the Sabatier reactor effluent, the PPA helps to minimize life support resupply costs for extended duration missions. To date, second generation PPA development has demonstrated significant technology advancements over the first generation device by doubling the methane processing rate while, at the same time, more than halving the required power. One development area of particular interest to NASA system engineers is fouling of the PPA reactor with carbonaceous products. As a mitigation plan, NASA MSFC has explored the feasibility of using an oxidative plasma based upon metabolic CO2 to regenerate the reactor window and gas inlet ports. The results and implications of this testing are addressed along with the advanced PPA reactor development.

Strategies to Optimize Microbially-Mediated Mitigation of Greenhouse Gas Emissions from Landfill Cover Soils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeremy Semrau; Sung-Woo Lee; Jeongdae Im

2010-09-30

The overall objective of this project, 'Strategies to Optimize Microbially-Mediated Mitigation of Greenhouse Gas Emissions from Landfill Cover Soils' was to develop effective, efficient, and economic methodologies by which microbial production of nitrous oxide can be minimized while also maximizing microbial consumption of methane in landfill cover soils. A combination of laboratory and field site experiments found that the addition of nitrogen and phenylacetylene stimulated in situ methane oxidation while minimizing nitrous oxide production. Molecular analyses also indicated that methane-oxidizing bacteria may play a significant role in not only removing methane, but in nitrous oxide production as well, although themore » contribution of ammonia-oxidizing archaea to nitrous oxide production can not be excluded at this time. Future efforts to control both methane and nitrous oxide emissions from landfills as well as from other environments (e.g., agricultural soils) should consider these issues. Finally, a methanotrophic biofiltration system was designed and modeled for the promotion of methanotrophic activity in local methane 'hotspots' such as landfills. Model results as well as economic analyses of these biofilters indicate that the use of methanotrophic biofilters for controlling methane emissions is technically feasible, and provided either the costs of biofilter construction and operation are reduced or the value of CO{sub 2} credits is increased, can also be economically attractive.« less

Sound management may sequester methane in grazed rangeland ecosystems

USDA-ARS?s Scientific Manuscript database

Considering their contribution to global warming, the sources and sinks of methane (CH4) should be accounted when undertaking a greenhouse gas inventory for grazed rangeland ecosystems. The aim of this study was to evaluate the mitigation potential of current ecological management programs implement...

Contribution of Anaerobic Digesters to Emissions Mitigation and Electricity Generation Under U.S. Climate Policy

PubMed Central

2011-01-01

Livestock husbandry in the U.S. significantly contributes to many environmental problems, including the release of methane, a potent greenhouse gas (GHG). Anaerobic digesters (ADs) break down organic wastes using bacteria that produce methane, which can be collected and combusted to generate electricity. ADs also reduce odors and pathogens that are common with manure storage and the digested manure can be used as a fertilizer. There are relatively few ADs in the U.S., mainly due to their high capital costs. We use the MIT Emissions Prediction and Policy Analysis (EPPA) model to test the effects of a representative U.S. climate stabilization policy on the adoption of ADs which sell electricity and generate methane mitigation credits. Under such policy, ADs become competitive at producing electricity in 2025, when they receive methane reduction credits and electricity from fossil fuels becomes more expensive. We find that ADs have the potential to generate 5.5% of U.S. electricity. PMID:21761880

Contribution of anaerobic digesters to emissions mitigation and electricity generation under U.S. climate policy.

PubMed

Zaks, David P M; Winchester, Niven; Kucharik, Christopher J; Barford, Carol C; Paltsev, Sergey; Reilly, John M

2011-08-15

Livestock husbandry in the U.S. significantly contributes to many environmental problems, including the release of methane, a potent greenhouse gas (GHG). Anaerobic digesters (ADs) break down organic wastes using bacteria that produce methane, which can be collected and combusted to generate electricity. ADs also reduce odors and pathogens that are common with manure storage and the digested manure can be used as a fertilizer. There are relatively few ADs in the U.S., mainly due to their high capital costs. We use the MIT Emissions Prediction and Policy Analysis (EPPA) model to test the effects of a representative U.S. climate stabilization policy on the adoption of ADs which sell electricity and generate methane mitigation credits. Under such policy, ADs become competitive at producing electricity in 2025, when they receive methane reduction credits and electricity from fossil fuels becomes more expensive. We find that ADs have the potential to generate 5.5% of U.S. electricity.

Influence of rumen protozoa on methane emission in ruminants: a meta-analysis approach.

PubMed

Guyader, J; Eugène, M; Nozière, P; Morgavi, D P; Doreau, M; Martin, C

2014-11-01

A meta-analysis was conducted to evaluate the effects of protozoa concentration on methane emission from ruminants. A database was built from 59 publications reporting data from 76 in vivo experiments. The experiments included in the database recorded methane production and rumen protozoa concentration measured on the same groups of animals. Quantitative data such as diet chemical composition, rumen fermentation and microbial parameters, and qualitative information such as methane mitigation strategies were also collected. In the database, 31% of the experiments reported a concomitant reduction of both protozoa concentration and methane emission (g/kg dry matter intake). Nearly all of these experiments tested lipids as methane mitigation strategies. By contrast, 21% of the experiments reported a variation in methane emission without changes in protozoa numbers, indicating that methanogenesis is also regulated by other mechanisms not involving protozoa. Experiments that used chemical compounds as an antimethanogenic treatment belonged to this group. The relationship between methane emission and protozoa concentration was studied with a variance-covariance model, with experiment as a fixed effect. The experiments included in the analysis had a within-experiment variation of protozoa concentration higher than 5.3 log10 cells/ml corresponding to the average s.e.m. of the database for this variable. To detect potential interfering factors for the relationship, the influence of several qualitative and quantitative secondary factors was tested. This meta-analysis showed a significant linear relationship between methane emission and protozoa concentration: methane (g/kg dry matter intake)=-30.7+8.14×protozoa (log10 cells/ml) with 28 experiments (91 treatments), residual mean square error=1.94 and adjusted R 2=0.90. The proportion of butyrate in the rumen positively influenced the least square means of this relationship.

Controlled Landfill Project in Yolo County, California for Environmental Benefits of Waste Stabilization and Minimization of Greenhouse Gas Emissions

NASA Astrophysics Data System (ADS)

Yazdani, R.; Augenstein, D.; Kieffer, J.; Cohen, K.

2003-12-01

The Department of Public Works of Yolo County, California, USA has been testing an advanced approach to landfill bioreactors, controlled (or "enhanced") landfilling, at its Yolo County Central Landfill site near Davis, CA, since 1994. Overall objectives have been the management of waste landfilling for: (1) rapid completion of total gas generation; (2) maximum, high-efficiency gas capture; (3) waste volume reduction; and (4) maximum greenhouse gas and carbon sequestration benefits. Methane generation is controlled and enhanced through carefully managed moisture additions, and by taking advantage of landfill temperature elevation. The generated landfill methane, an important greenhouse gas, is recovered with high efficiency through extraction from a porous recovery layer beneath a surface geomembrane cover. Instrumentation included a total of 56 moisture and 15 temperature sensors in the two cells, gas flow monitoring by positive displacement gas meters, and accurate quantification of liquid inputs and outputs. Gas composition, waste volume reduction, base hydrostatic head, and a range of environmental compliance parameters has been monitored since 1995. Partitioning gas tracer tests using the injection of two gases at dilute concentrations in the landfill have also been initiated to compute the fraction of pore space occupied by water between the points of tracer injection and tracer measurement. There has been rapid waste volume reduction in the enhanced cell that corresponds to the solids' reduction to gas. Monitoring is planned for the next several years, until stabilization parameters are determined complete. Encouraging performance is indicated by: (1) sensor data; (2) gas generation results; (3) data from landfill cores; and (4) decomposition-related indicators including rapid volume reduction. When data are synthesized, project results have attractive implications for new approaches to landfill management. Over seven-years, methane recoveries have averaged over fivefold the "typical" values for comparable landfill waste. In terms of "greenhouse benefit," fractional VOC and methane energy recovery are estimated to exceed 90%, with corresponding methane and VOC emission reductions. Analyses done for the greenhouse gas mitigation program of the U.S. Department of Energy National Energy Technology Laboratory indicate favorable economics justified on landfill life extension, as well as environmental benefits. The "controlled landfill" project findings suggest potential for low-cost mitigation of waste greenhouse methane emissions, maximum landfill carbon sequestration, and maximization of beneficial energy capture from landfills. Details and results obtained since 1994 will be presented.

In vitro screening of selected feed additives, plant essential oils and plant extracts for rumen methane mitigation.

PubMed

Durmic, Zoey; Moate, Peter J; Eckard, Richard; Revell, Dean K; Williams, Richard; Vercoe, Philip E

2014-04-01

Ruminants produce large quantities of methane in their rumen as a by-product of microbial digestion of feed. Antibiotics are added to ruminant feed to reduce wasteful production of methane; however, this practice has some downsides. A search for safer and natural feed additives with anti-methanogenic properties is under way. The objective of this research was to examine selected feed additives, plant essential oils and plant extracts for their anti-methanogenic potential in the rumen using an in vitro batch fermentation system. A significant reduction (P < 0.05) in methane production was observed with nine feed additives (up to 40% reduction), all eight essential oils (up to 75% reduction) and two plant extracts (14% reduction) when compared to their respective controls. Amongst these, only an algal meal high in docosahexaenoic acid, preparations of Nannochloropsis oculata, calcareous marine algae, yeast metabolites and two tannins did not inhibit microbial gas and volatile acid production. The current study identified some potent dietary ingredients or plant compounds that can assist in developing novel feed additives for methane mitigation from the rumen. © 2013 Society of Chemical Industry.

Methane Recovery from Animal Manures The Current Opportunities Casebook

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lusk, P.

1998-09-01

Growth and concentration of the livestock industry create opportunities for the proper disposal of the large quantities of manures generated at dairy, swine, and poultry farms. Pollutants from unmanaged livestock wastes can degrade the environment, and methane emitted from decomposing manure may contribute to global climate change. One management system not only provides pollution prevention but also can convert a manure problem into a new profit center. Economic evaluations and case studies of operating systems indicate that the anaerobic digestion (AD) of livestock manures is a commercially available bioconversion technology with considerable potential for providing profitable coproducts, including a cost-effectivemore » renewable fuel for livestock production operations. This Casebook examines some of the current opportunities for the recovery of methane from the AD animal manures. U.S. livestock operations currently employ four types of anaerobic digester technology: slurry, plug-flow, complete-mix, and covered lagoon. An introduction to the engineering economies of these technologies is provided, and possible end-use applications for the methane gas generated by the digestion process are discussed. The economic evaluations are based on engineering studies of digesters that generate electricity from the recovered methane. Case studies of operating digesters, with project and maintenance histories and the operators ''lessons learned,'' are included as reality checks. Factors necessary for successful projects, as well as a list of reasons explaining why some AD projects fail, are provided. The role of farm management is key; not only must digesters be well engineered and built with high-quality components, they must also be sited at farms willing to incorporate the uncertainties of a new technology. More than two decades of research has provided much information about how manure can be converted to an energy source; however, the American farmer has not been motivated to adopt new practices. More cost-effective and easily managed manure management techniques are still needed to encourage farmers to use animal manure for conversion into energy and nutrients, especially for smaller farms. AD benefits farmers monetarily and mitigates possible manure pollution problems, thereby sustaining development while maintaining environmental quality. Moreover, rural economic development will benefit from the implicit multiplier effect resulting from jobs created by implementing digester systems. Promising future waste-to-profit activities may add to the economic performance of AD. New end-use applications, which provide added value to coproducts, are discussed.« less

GHG emissions and mitigation potential in Indian agriculture

NASA Astrophysics Data System (ADS)

Vetter, Sylvia; Feliciano, Diana; Sapkota, Tek; Hillier, Jon; Smith, Pete; Stirling, Clare

2016-04-01

India is one of the world's largest greenhouse gas (GHG) emitter, accounting for about 5% of global emissions with further increases expected in the future. The Government of India aims to reduce emission intensities by 20-25% by 2020 compared with the 2005 level. In a recent departure from past practice the reconvened Council on Climate Change stated that climate change in agriculture would include a component that would focus on reducing emissions in agriculture, particularly methane and nitrous oxide emissions. To develop recommendations for mitigation in agriculture in India, a baseline study is presented to analyse the GHG emissions from agriculture for current management (Directorate of Economics and Statistics of the government of India). This analysis is done for the two states Bihar and Haryana, which differ in their management and practises based on different climate and policies. This first analysis shows were the highest GHG emissions in agriculture is produced and were the highest mitigation potential might be. The GHG emissions and mitigation potential are calculated using the CCAFS Mitigation Option Tool (CCAFS-MOT) (https://ccafs.cgiar.org/mitigation-option-tool-agriculture#.VpTnWL826d4) with modifications for the special modelling. In a second step, stakeholder meetings provided a wide range of possible and definite scenarios (management, policy, technology, costs, etc.) for the future to mitigate emissions in agriculture as well as how to increase productivity. These information were used to create scenarios to give estimates for the mitigation potential in agriculture for India in 2020.

Principal Factors for High Performance of Odor and Methane degrading Biocover using Network Analysis

NASA Astrophysics Data System (ADS)

Jung, H.; Yun, J.; O, G. C.; Ryu, H. W.; Jeon, J. M.; Cho, K. S.

2016-12-01

Methane is 25 times more powerful greenhouse gas than carbon dioxide and plays an important role in global warming. Landfills are one of the biggest methane sources and have emitted 37% of anthropogenic methane in Korea. Applying biocovers in landfills is known to be efficient for the simultaneous mitigation of methane as well as odor which occurs severe civil claims. In this study, three pilot-scale biocovers (2.5mx5mx1m) were constructed in a sanitary landfill at Gwangyang, Korea to establish the optimal operational conditions of biocover. All biocovers are filled with soil, EG microbial agent, food waste compost, and perlite with different combination. Pilot-scale biocovers have been operated since January in this year for simultaneous removal of odor and methane. The concentrations of methane and odors such as ammonia, H2S, methyl mercaptane, methylsulfide, dimetyl disulfide, i-valeraldehyde, and styrene were measured at the inlet and outlet of biocovers each month using GC and HPLC for removal performance evaluation. The biocover with highest removal efficiency eliminated 98.4% of odor and 100.0% of methane. All removal efficiencies of odor measured during experiment are in 81.1 98.4% range, and those of methane are in 3.6 100.0%. Three months later after biocover construction, all biocovers with mixed packing material showed better methane degradation performance than the biocovers packed only with soil. The packing materials of biocovers were sampled during winter (January), spring (April) and summer (July), and their microbial communities were examined based on 16S rDNA using 454 pyrosequencing to detect microbial factors that affects the removal efficiency. Methanotrophs which are known as methane-degradable bacteria take 10 25% of microbial community in biocovers, and most of those found in biocovers are type methanothrophs. Network analysis is performed and principal factors for performance improvement of biocovers are derived. Based on this study, well-designed biocovers will be newly set up in the operational landfill with the consideration of derived principal factors for high efficiency. This research was supported by the Korea Ministry of Environment as a "Converging Technology Project (2015001640003)".

Animal and industrial waste anaerobic digestion: USA status report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lusk, P.D.

1996-01-01

Pollutants from unmanaged animal and bio-based industrial wastes can degrade the environment, and methane emitted from decomposing wastes may contribute to global climate change. One waste management system prevents pollution and converts a disposal problem into a new profit center. Case studies of operating systems indicate that the anaerobic digestion of animal and industrial wastes is a commercially available bioconversion technology with considerable potential for providing profitable coproducts, including a cost-effective renewable fuel. Growth and concentration of the livestock industry create opportunities to properly dispose of the large quantities of manures generated at dairy, swine, and poultry farms. Beyond themore » farm, extension of the anaerobic digestion process to recover methane has considerable potential for certain classified industries - with a waste stream characterization similar to livestock manures. More than 35 example industries have been identified, and include processors of chemicals, fiber, food, meat, milk, and pharmaceuticals. Some of these industries already recover methane for energy. This status report examines some current opportunities for recovering methane from the anaerobic digestion of animal and industrial wastes in the US. Case studies of operating digesters, including project and maintenance histories, and the operator`s {open_quotes}lessons learned,{close_quotes} are included as a reality check. Factors necessary for successful projects, as well as a list of reasons explaining why some anaerobic digestion projects fail, are provided. The role of management is key; not only must digesters be well engineered and built with high-quality components, they must also be sited at facilities willing to incorporate the uncertainties of a new technology. Anaerobic digestion can provide monetary benefits and mitigate possible pollution problems, thereby sustaining development while maintaining environmental quality.« less

Advances in Estimating Methane Emissions from Enteric Fermentation

NASA Astrophysics Data System (ADS)

Kebreab, E.; Appuhamy, R.

2016-12-01

Methane from enteric fermentation of livestock is the largest contributor to the agricultural GHG emissions. The quantification of methane emissions from livestock on a global scale relies on prediction models because measurements require specialized equipment and may be expensive. Most countries use a fixed number (kg methane/year) or calculate as a proportion of energy intake to estimate enteric methane emissions in national inventories. However, diet composition significantly regulates enteric methane production in addition to total feed intake and thus the main target in formulating mitigation options. The two current methodologies are not able to assess mitigation options, therefore, new estimation methods are required that can take feed composition into account. The availability of information on livestock production systems has increased substantially enabling the development of more detailed methane prediction models. Limited number of process-based models have been developed that represent biological relationships in methane production, however, these require extensive inputs and specialized software that may not be easily available. Empirical models may provide a better alternative in practical situations due to less input requirements. Several models have been developed in the last 10 years but none of them work equally well across all regions of the world. The more successful models particularly in North America require three major inputs: feed (or energy) intake, fiber and fat concentration of the diet. Given the significant variability of emissions within regions, models that are able to capture regional variability of feed intake and diet composition perform the best in model evaluation with independent data. The utilization of such models may reduce uncertainties associated with prediction of methane emissions and allow a better examination and representation of policies regulating emissions from cattle.

Effect of bio-column composed of aged refuse on methane abatement--a novel configuration of biological oxidation in refuse landfill.

PubMed

Han, Dan; Zhao, Youcai; Xue, Binjie; Chai, Xiaoli

2010-01-01

An experimental bio-column composed of aged refuse was installed around the exhaust pipe as a new way to mitigate methane in refuse landfill. One of the objectives of this work was to assess the effect of aged refuse thickness in bio-column on reducing CH4 emissions. Over the study period, methane oxidation was observed at various thicknesses, 5 cm (small size), 10 cm (middle size) and 15 cm (large size), representing one to three times of pipeline diameters. The middle and large size both showed over 90% methane conversion, and the highest methane conversion rate of above 95% occurred in the middle-size column cell. Michaelis-Menten equation addressed the methanotrophs diffusion in different layers of the bio-columns. Maximum methanotrophic activity (Vmax) measured at the three thicknesses ranged from 6.4 x 10(-3) to 15.6 x 10(-3) units, and the half-saturation value (K(M)) ranged from 0.85% to 1.67%. Both the highest Vmax and K(M) were observed at the middle-size of the bio-column, as well as the largest methanotrophs population, suggesting a significant efficiency of methane mitigation happened in the optimum zone with greatest affinity and methanotrophic bacteria activities. Therefore, bio-column is a potential style for methane abatement in landfill, and the aged refuse both naturally formed and artificially placed in the column plays a critical role in CH4 emission.

Understanding the contribution of non-carbon dioxide gases in deep mitigation scenarios

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gernaat, David; Calvin, Katherine V.; Lucas, Paul

2015-07-01

The combined 2010 emissions of methane (CH4), nitrous oxide (N2O) and the fluorinated gasses (F-gas) account for about 20-30% of total emissions and about 30% of radiative forcing. At the moment, most studies looking at reaching ambitious climate targets project the emission of carbon dioxide (CO2) to be reduced to zero (or less) by the end of the century. As for non-CO2 gases, the mitigation potential seem to be more constrained, we find that by the end of the century in the current deep mitigation scenarios non-CO2 emissions could form the lion’s share of remaining greenhouse gas emissions. In ordermore » to support effective climate policy strategies, in this paper we provide a more in-depth look at the role of non-CO2¬ emission sources (CH4, N2O and F-gases) in achieving deep mitigation targets (radiative forcing target of 2.8 W/m2 in 2100). Specifically, we look at the sectorial mitigation potential and the remaining non-CO2 emissions. By including a set of different models, we provide some insights into the associated uncertainty. Most of the remaining methane emissions in 2100 in the climate mitigation scenario come from the livestock sector. Strong reductions are seen in the energy supply sector across all models. For N2O, less reduction potential is seen compared to methane and the sectoral differences are larger between the models. The paper shows that the assumptions on remaining non-CO2 emissions are critical for the feasibility of reaching ambitious climate targets and the associated costs.« less

Effect of unconventional oilseeds (safflower, poppy, hemp, camelina) on in vitro ruminal methane production and fermentation.

PubMed

Wang, Shaopu; Kreuzer, Michael; Braun, Ueli; Schwarm, Angela

2017-08-01

Dietary supplementation with oilseeds can reduce methane emission in ruminants, but only a few common seeds have been tested so far. This study tested safflower (Carthamus tinctorius), poppy (Papaver somniferum), hemp (Cannabis sativa), and camelina (Camelina sativa) seeds in vitro using coconut (Cocos nucifera) oil and linseed (Linum usitatissimum) as positive controls. All the tested oilseeds suppressed methane yield (mL g -1 dry matter, up to 21%) compared to the non-supplemented control when provided at 70 g oil kg -1 dry matter, and they were as effective as coconut oil. Safflower and hemp were more effective than linseed (21% and 18% vs. 10%), whereas the effects of poppy and camelina were similar to linseed. When methane was related to digestible organic matter, only hemp and safflower seeds and coconut oil were effective compared to the non-supplemented control (up to 11%). The level of methanogenesis and the ratios of either the n-6:n-3 fatty acids or C 18 :2 :C 18 :3 in the seed lipids were not related. Unconventional oilseeds widen the spectrum of oilseeds that can be used in dietary methane mitigation. In vivo confirmation of their methane mitigating effect is still needed, and their effects on animal performance still must be determined. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

TECHNICAL NOTE: Effect of bait delivery interval in an automated head-chamber system on respiration gas estimates when cattle are grazing rangeland

USDA-ARS?s Scientific Manuscript database

Agricultural methane emissions account for approximately 43% of all anthropogenic methane emissions and the majority of agricultural CH4 emissions are attributed to enteric fermentation within ruminant livestock, therefor interest is heightened in quantifying and mitigating this source. An automate...

Seasonal methane and nitrous oxide emissions of several rice cultivars in direct-seeded systems

USDA-ARS?s Scientific Manuscript database

Understanding cultivar effects on field greenhouse gas (GHG) emissions in rice (Oryza sativa L.) systems is needed to improve the accuracy of predictive models used for estimating GHG emissions and determine to what extent choice of cultivar may have on GHG mitigation. We compared methane (CH4) and...

Methane Emissions from Reservoirs: Assessing the Magnitude and Developing Mitigation Approaches

EPA Science Inventory

Although methane can be emitted from a number of natural sources, it is the second most important greenhouse gas emitted from human-related activities and has a heat trapping capacity 34 times greater than that of carbon dioxide on a 100 year time scale. The U.S. Greenhouse Gas I...

Studies of methane fluxes reveal that desert soils can mitigate global climate change

Treesearch

Jean E. T. McLain; Dean A. Martens

2005-01-01

Moisture limitations have led researchers to believe that semiarid soils are not significant consumers or producers of trace gases, and these regions are often overlooked in greenhouse gas inventories. We are studying environmental influences on soil fluxes of methane (CH4) in southeastern Arizona. We found negligible CH4...

Potential for reduced methane and carbon dioxide emissions from livestock and pasture management in the tropics

PubMed Central

Thornton, Philip K.; Herrero, Mario

2010-01-01

We estimate the potential reductions in methane and carbon dioxide emissions from several livestock and pasture management options in the mixed and rangeland-based production systems in the tropics. The impacts of adoption of improved pastures, intensifying ruminant diets, changes in land-use practices, and changing breeds of large ruminants on the production of methane and carbon dioxide are calculated for two levels of adoption: complete adoption, to estimate the upper limit to reductions in these greenhouse gases (GHGs), and optimistic but plausible adoption rates taken from the literature, where these exist. Results are expressed both in GHG per ton of livestock product and in Gt CO2-eq. We estimate that the maximum mitigation potential of these options in the land-based livestock systems in the tropics amounts to approximately 7% of the global agricultural mitigation potential to 2030. Using historical adoption rates from the literature, the plausible mitigation potential of these options could contribute approximately 4% of global agricultural GHG mitigation. This could be worth on the order of $1.3 billion per year at a price of $20 per t CO2-eq. The household-level and sociocultural impacts of some of these options warrant further study, however, because livestock have multiple roles in tropical systems that often go far beyond their productive utility. PMID:20823225

Experimental evaluation and analysis of methane fire and explosion mitigation using isolation valves integrated with a vent system.

PubMed

Ajrash, Mohammed J; Zanganeh, Jafar; Moghtaderi, Behdad

2017-10-05

There has been a surge of interest from the extractive industries in the application of mechanical means to the mitigation of flame deflagration. To verify the implementation and performance of passive and active mitigation protection, a comprehensive experimental investigation has been conducted on a large scale detonation tube, 30m long and 0.5m in diameter, with two mitigation valves (passive and active) and a burst panel venting system. The valves were used alternately to mitigate the flame deflagration of methane in concentrations ranging from 1.25% to 7.5%. The experimental work revealed that locating the passive mitigation valve at 22m distance from the ignition source mitigates the flame by fully isolating the tube. However, closing the valve structure in the axial direction generated another pressure wave upstream, which was approximately the same value as for the original pressure wave upstream. In the case of the active mitigation system, the system perfectly isolated upstream from downstream with no further pressure wave generation. When the vent was located at 6.5m from the ignition source, the total pressure was reduced by 0.48bar. Due to the counter flow of the reflected pressure wave the flame was extinguished at 12.5m from the ignition source. Copyright © 2017 Elsevier B.V. All rights reserved.

The regulation of methane oxidation in soil

NASA Technical Reports Server (NTRS)

Mancinelli, R. L.

1995-01-01

The atmospheric concentration of methane, a greenhouse gas, has more than doubled during the past 200 years. Consequently, identifying the factors influencing the flux of methane into the atmosphere is becoming increasingly important. Methanotrophs, microaerophilic organisms widespread in aerobic soils and sediments, oxidize methane to derive energy and carbon for biomass. In so doing, they play an important role in mitigating the flux of methane into the atmosphere. Several physico-chemical factors influence rates of methane oxidation in soil, including soil diffusivity; water potential; and levels of oxygen, methane, ammonium, nitrate, nitrite, and copper. Most of these factors exert their influence through interactions with methane monooxygenase (MMO), the enzyme that catalyzes the reaction converting methane to methanol, the first step in methane oxidation. Although biological factors such as competition and predation undoubtedly play a role in regulating the methanotroph population in soils, and thereby limit the amount of methane consumed by methanotrophs, the significance of these factors is unknown. Obtaining a better understanding of the ecology of methanotrophs will help elucidate the mechanisms that regulate soil methane oxidation.

Microbial oxidation as a methane sink beneath the West Antarctic Ice Sheet

NASA Astrophysics Data System (ADS)

Michaud, Alexander B.; Dore, John E.; Achberger, Amanda M.; Christner, Brent C.; Mitchell, Andrew C.; Skidmore, Mark L.; Vick-Majors, Trista J.; Priscu, John C.

2017-08-01

Aquatic habitats beneath ice masses contain active microbial ecosystems capable of cycling important greenhouse gases, such as methane (CH4). A large methane reservoir is thought to exist beneath the West Antarctic Ice Sheet, but its quantity, source and ultimate fate are poorly understood. For instance, O2 supplied by basal melting should result in conditions favourable for aerobic methane oxidation. Here we use measurements of methane concentrations and stable isotope compositions along with genomic analyses to assess the sources and cycling of methane in Subglacial Lake Whillans (SLW) in West Antarctica. We show that sub-ice-sheet methane is produced through the biological reduction of CO2 using H2. This methane pool is subsequently consumed by aerobic, bacterial methane oxidation at the SLW sediment-water interface. Bacterial oxidation consumes >99% of the methane and represents a significant methane sink, and source of biomass carbon and metabolic energy to the surficial SLW sediments. We conclude that aerobic methanotrophy may mitigate the release of methane to the atmosphere upon subglacial water drainage to ice sheet margins and during periods of deglaciation.

Carbon isotope equilibration during sulphate-limited anaerobic oxidation of methane

NASA Astrophysics Data System (ADS)

Yoshinaga, Marcos Y.; Holler, Thomas; Goldhammer, Tobias; Wegener, Gunter; Pohlman, John W.; Brunner, Benjamin; Kuypers, Marcel M. M.; Hinrichs, Kai-Uwe; Elvert, Marcus

2014-03-01

Collectively, marine sediments comprise the largest reservoir of methane on Earth. The flux of methane from the sea bed to the overlying water column is mitigated by the sulphate-dependent anaerobic oxidation of methane by marine microbes within a discrete sedimentary horizon termed the sulphate-methane transition zone. According to conventional isotope systematics, the biological consumption of methane leaves a residue of methane enriched in 13C (refs , , ). However, in many instances the methane within sulphate-methane transition zones is depleted in 13C, consistent with the production of methane, and interpreted as evidence for the intertwined anaerobic oxidation and production of methane. Here, we report results from experiments in which we incubated cultures of microbial methane consumers with methane and low levels of sulphate, and monitored the stable isotope composition of the methane and dissolved inorganic carbon pools over time. Residual methane became progressively enriched in 13C at sulphate concentrations above 0.5 mM, and progressively depleted in 13C below this threshold. We attribute the shift to 13C depletion during the anaerobic oxidation of methane at low sulphate concentrations to the microbially mediated carbon isotope equilibration between methane and carbon dioxide. We suggest that this isotopic effect could help to explain the 13C-depletion of methane in subseafloor sulphate-methane transition zones.

Bioelectrochemical approach for control of methane emission from wetlands.

PubMed

Liu, Shentan; Feng, Xiaojuan; Li, Xianning

2017-10-01

To harvest electricity and mitigate methane emissions from wetlands, a novel microbial fuel cell coupled constructed wetland (MFC-CW) was assembled with an anode placing in the rhizosphere and a cathode on the water surface. Plant-mediated methane accounted for 71-82% of the total methane fluxes. The bioanode served as an inexhaustible source of electron acceptors and resulted in reduced substantial methane emissions owing to electricigens outcompeting methanogens for carbon and electrons when substrate was deficient. However, when supplying sufficient organic carbon, both electricity and methane increased, indicating that electrogenesis and methanogenesis could co-exist in harmony. Direct methane emission (diffusion/ebullition) and plant-mediated methane emission were affected by operating conditions. Methanogenesis was significantly suppressed (∼98%) at HRT of 96h and with external resistance of 200Ω, accompanied with improved coulombic efficiency of 14.9% and current density of 187mA/m 2 . Contrarily, change of electrode polarity in the rhizosphere led to more methane efflux. Copyright © 2017 Elsevier Ltd. All rights reserved.

Measurement of methane fluxes from terrestrial landscapes using static, non-steady state enclosures. Chapter 12

Treesearch

Peter Weishampel; Randall Kolka

2008-01-01

Wetlands are a dominant natural source of atmospheric methane (CH4), a potent greenhouse gas whose concentration in the atmosphere has doubled over the past 150 years. Evaluating the impacts of CH4 emissions on global climate and developing policies to mitigate those impacts requires a quantifiable and predictive...

Mitigation of ammonia, nitrous oxide and methane emissions from manure management chains: a meta-analysis and integrated assessment.

PubMed

Hou, Yong; Velthof, Gerard L; Oenema, Oene

2015-03-01

Livestock manure contributes considerably to global emissions of ammonia (NH3 ) and greenhouse gases (GHG), especially methane (CH4 ) and nitrous oxide (N2 O). Various measures have been developed to mitigate these emissions, but most of these focus on one specific gas and/or emission source. Here, we present a meta-analysis and integrated assessment of the effects of mitigation measures on NH3 , CH4 and (direct and indirect) N2 O emissions from the whole manure management chain. We analysed the effects of mitigation technologies on NH3 , CH4 and N2 O emissions from individual sources statistically using results of 126 published studies. Whole-chain effects on NH3 and GHG emissions were assessed through scenario analysis. Significant NH3 reduction efficiencies were observed for (i) housing via lowering the dietary crude protein (CP) content (24-65%, compared to the reference situation), for (ii) external slurry storages via acidification (83%) and covers of straw (78%) or artificial films (98%), for (iii) solid manure storages via compaction and covering (61%, compared to composting), and for (iv) manure application through band spreading (55%, compared to surface application), incorporation (70%) and injection (80%). Acidification decreased CH4 emissions from stored slurry by 87%. Significant increases in N2 O emissions were found for straw-covered slurry storages (by two orders of magnitude) and manure injection (by 26-199%). These side-effects of straw covers and slurry injection on N2 O emission were relatively small when considering the total GHG emissions from the manure chain. Lowering the CP content of feed and acidifying slurry are strategies that consistently reduce NH3 and GHG emissions in the whole chain. Other strategies may reduce emissions of a specific gas or emissions source, by which there is a risk of unwanted trade-offs in the manure management chain. Proper farm-scale combinations of mitigation measures are important to minimize impacts of livestock production on global emissions of NH3 and GHG. © 2014 John Wiley & Sons Ltd.

The social cost of methane: theory and applications.

PubMed

Shindell, D T; Fuglestvedt, J S; Collins, W J

2017-08-24

Methane emissions contribute to global warming, damage public health and reduce the yield of agricultural and forest ecosystems. Quantifying these damages to the planetary commons by calculating the social cost of methane (SCM) facilitates more comprehensive cost-benefit analyses of methane emissions control measures and is the first step to potentially incorporating them into the marketplace. Use of a broad measure of social welfare is also an attractive alternative or supplement to emission metrics focused on a temperature target in a given year as it incentivizes action to provide benefits over a broader range of impacts and timescales. Calculating the SCM using consistent temporal treatment of physical and economic processes and incorporating climate- and air quality-related impacts, we find large SCM values, e.g. ∼$2400 per ton and ∼$3600 per ton with 5% and 3% discount rates respectively. These values are ∼100 and 50 times greater than corresponding social costs for carbon dioxide. Our results suggest that ∼110 of 140 Mt of identified methane abatement via scaling up existing technology and policy options provide societal benefits that outweigh implementation costs. Within the energy sector, renewables compare far better against use of natural gas in electricity generation when incorporating these social costs for methane. In the agricultural sector, changes in livestock management practices, promoting healthy diets including reduced beef and dairy consumption, and reductions in food waste have been promoted as ways to mitigate emissions, and these are shown here to indeed have the potential to provide large societal benefits (∼$50-150 billion per year). Examining recent trends in methane and carbon dioxide, we find that increases in methane emissions may have offset much of the societal benefits from a slowdown in the growth rate of carbon dioxide emissions. The results indicate that efforts to reduce methane emissions via policies spanning a wide range of technical, regulatory and behavioural options provide benefits at little or negative net cost. Recognition of the full SCM, which has typically been undervalued, may help catalyze actions to reduce emissions and thereby provide a broad set of societal benefits.

Atmospheric methane removal by methane-oxidizing bacteria immobilized on porous building materials.

PubMed

Ganendra, Giovanni; De Muynck, Willem; Ho, Adrian; Hoefman, Sven; De Vos, Paul; Boeckx, Pascal; Boon, Nico

2014-04-01

Biological treatment using methane-oxidizing bacteria (MOB) immobilized on six porous carrier materials have been used to mitigate methane emission. Experiments were performed with different MOB inoculated in building materials at high (~20 % (v/v)) and low (~100 ppmv) methane mixing ratios. Methylocystis parvus in autoclaved aerated concrete (AAC) exhibited the highest methane removal rate at high (28.5 ± 3.8 μg CH₄ g⁻¹ building material h⁻¹) and low (1.7 ± 0.4 μg CH₄ g⁻¹ building material h⁻¹) methane mixing ratio. Due to the higher volume of pores with diameter >5 μm compared to other materials tested, AAC was able to adsorb more bacteria which might explain for the higher methane removal observed. The total methane and carbon dioxide-carbon in the headspace was decreased for 65.2 ± 10.9 % when M. parvus in Ytong was incubated for 100 h. This study showed that immobilized MOB on building materials could be used to remove methane from the air and also act as carbon sink.

The impact of shale gas on the cost and feasibility of meeting climate targets—A global energy system model analysis and an exploration of uncertainties

DOE PAGES

Few, Sheridan; Gambhir, Ajay; Napp, Tamaryn; ...

2017-01-27

There exists considerable uncertainty over both shale and conventional gas resource availability and extraction costs, as well as the fugitive methane emissions associated with shale gas extraction and its possible role in mitigating climate change. This study uses a multi-region energy system model, TIAM (TIMES integrated assessment model), to consider the impact of a range of conventional and shale gas cost and availability assessments on mitigation scenarios aimed at achieving a limit to global warming of below 2 °C in 2100, with a 50% likelihood. When adding shale gas to the global energy mix, the reduction to the global energymore » system cost is relatively small (up to 0.4%), and the mitigation cost increases by 1%–3% under all cost assumptions. The impact of a “dash for shale gas”, of unavailability of carbon capture and storage, of increased barriers to investment in low carbon technologies, and of higher than expected leakage rates, are also considered; and are each found to have the potential to increase the cost and reduce feasibility of meeting global temperature goals. Finally, we conclude that the extraction of shale gas is not likely to significantly reduce the effort required to mitigate climate change under globally coordinated action, but could increase required mitigation effort if not handled sufficiently carefully.« less

The impact of shale gas on the cost and feasibility of meeting climate targets—A global energy system model analysis and an exploration of uncertainties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Few, Sheridan; Gambhir, Ajay; Napp, Tamaryn

There exists considerable uncertainty over both shale and conventional gas resource availability and extraction costs, as well as the fugitive methane emissions associated with shale gas extraction and its possible role in mitigating climate change. This study uses a multi-region energy system model, TIAM (TIMES integrated assessment model), to consider the impact of a range of conventional and shale gas cost and availability assessments on mitigation scenarios aimed at achieving a limit to global warming of below 2 °C in 2100, with a 50% likelihood. When adding shale gas to the global energy mix, the reduction to the global energymore » system cost is relatively small (up to 0.4%), and the mitigation cost increases by 1%–3% under all cost assumptions. The impact of a “dash for shale gas”, of unavailability of carbon capture and storage, of increased barriers to investment in low carbon technologies, and of higher than expected leakage rates, are also considered; and are each found to have the potential to increase the cost and reduce feasibility of meeting global temperature goals. Finally, we conclude that the extraction of shale gas is not likely to significantly reduce the effort required to mitigate climate change under globally coordinated action, but could increase required mitigation effort if not handled sufficiently carefully.« less

Mitigation of methane emissions in cities: How new measurements and partnerships can contribute to emissions reduction strategies

NASA Astrophysics Data System (ADS)

Hopkins, Francesca M.; Ehleringer, James R.; Bush, Susan E.; Duren, Riley M.; Miller, Charles E.; Lai, Chun-Ta; Hsu, Ying-Kuang; Carranza, Valerie; Randerson, James T.

2016-09-01

Cities generate 70% of anthropogenic greenhouse gas emissions, a fraction that is growing with global urbanization. While cities play an important role in climate change mitigation, there has been little focus on reducing urban methane (CH4) emissions. Here, we develop a conceptual framework for CH4 mitigation in cities by describing emission processes, the role of measurements, and a need for new institutional partnerships. Urban CH4 emissions are likely to grow with expanding use of natural gas and organic waste disposal systems in growing population centers; however, we currently lack the ability to quantify this increase. We also lack systematic knowledge of the relative contribution of these distinct source sectors on emissions. We present new observations from four North American cities to demonstrate that CH4 emissions vary in magnitude and sector from city to city and hence require different mitigation strategies. Detections of fugitive emissions from these systems suggest that current mitigation approaches are absent or ineffective. These findings illustrate that tackling urban CH4 emissions will require research efforts to identify mitigation targets, develop and implement new mitigation strategies, and monitor atmospheric CH4 levels to ensure the success of mitigation efforts. This research will require a variety of techniques to achieve these objectives and should be deployed in cities globally. We suggest that metropolitan scale partnerships may effectively coordinate systematic measurements and actions focused on emission reduction goals.

Global Air Quality and Health Co-benefits of Mitigating Near-term Climate Change Through Methane and Black Carbon Emission Controls

NASA Technical Reports Server (NTRS)

Anenberg, Susan C.; Schwartz, Joel; Shindell, Drew Todd; Amann, Markus; Faluvegi, Gregory S.; Klimont, Zbigniew; Janssens-Maenhout, Greet; Pozzoli, Luca; Dingenen, Rita Van; Vignati, Elisabetta;

Global Air Quality and Health Co-benefits of Mitigating Near-Term Climate Change through Methane and Black Carbon Emission Controls

PubMed Central

Schwartz, Joel; Shindell, Drew; Amann, Markus; Faluvegi, Greg; Klimont, Zbigniew; Janssens-Maenhout, Greet; Pozzoli, Luca; Van Dingenen, Rita; Vignati, Elisabetta; Emberson, Lisa; Muller, Nicholas Z.; West, J. Jason; Williams, Martin; Demkine, Volodymyr; Hicks, W. Kevin; Kuylenstierna, Johan; Raes, Frank; Ramanathan, Veerabhadran

2012-01-01

Background: Tropospheric ozone and black carbon (BC), a component of fine particulate matter (PM ≤ 2.5 µm in aerodynamic diameter; PM2.5), are associated with premature mortality and they disrupt global and regional climate. Objectives: We examined the air quality and health benefits of 14 specific emission control measures targeting BC and methane, an ozone precursor, that were selected because of their potential to reduce the rate of climate change over the next 20–40 years. Methods: We simulated the impacts of mitigation measures on outdoor concentrations of PM2.5 and ozone using two composition-climate models, and calculated associated changes in premature PM2.5- and ozone-related deaths using epidemiologically derived concentration–response functions. Results: We estimated that, for PM2.5 and ozone, respectively, fully implementing these measures could reduce global population-weighted average surface concentrations by 23–34% and 7–17% and avoid 0.6–4.4 and 0.04–0.52 million annual premature deaths globally in 2030. More than 80% of the health benefits are estimated to occur in Asia. We estimated that BC mitigation measures would achieve approximately 98% of the deaths that would be avoided if all BC and methane mitigation measures were implemented, due to reduced BC and associated reductions of nonmethane ozone precursor and organic carbon emissions as well as stronger mortality relationships for PM2.5 relative to ozone. Although subject to large uncertainty, these estimates and conclusions are not strongly dependent on assumptions for the concentration–response function. Conclusions: In addition to climate benefits, our findings indicate that the methane and BC emission control measures would have substantial co-benefits for air quality and public health worldwide, potentially reversing trends of increasing air pollution concentrations and mortality in Africa and South, West, and Central Asia. These projected benefits are independent of carbon dioxide mitigation measures. Benefits of BC measures are underestimated because we did not account for benefits from reduced indoor exposures and because outdoor exposure estimates were limited by model spatial resolution. PMID:22418651

Comparing top-down and bottom-up estimates of methane emissions across multiple U.S. oil and gas basins provides insights into national O&G emissions, mitigation strategies, and research priorities

NASA Astrophysics Data System (ADS)

Lyon, D. R.; Alvarez, R.; Zavala Araiza, D.; Hamburg, S.

2017-12-01

We develop a county-level inventory of U.S. anthropogenic methane emissions by integrating multiple data sources including the Drillinginfo oil and gas (O&G) production database, Environmental Protection Agency (EPA) Greenhouse Gas Reporting Program, a previously published gridded EPA Greenhouse Gas Inventory (Maasakkers et al 2016), and recent measurements studies of O&G pneumatic devices, equipment leaks, abandoned wells, and midstream facilities. Our bottom-up estimates of total and O&G methane emissions are consistently lower than top-down, aerial mass balance estimates in ten O&G production areas. We evaluate several hypotheses for the top-down/bottom-up discrepancy including potential bias of the aerial mass balance method, temporal mismatch of top-down and bottom-up emission estimates, and source attribution errors. In most basins, the top-down/bottom-up gap cannot be explained fully without additional O&G emissions from sources not included in traditional inventories, such as super-emitters caused by malfunctions or abnormal process conditions. Top-down/bottom-up differences across multiple basins are analyzed to estimate the magnitude of these additional emissions and constrain total methane emissions from the U.S. O&G supply chain. We discuss the implications for mitigating O&G methane emissions and suggest research priorities for increasing the accuracy of future emission inventories.

Effect of Nitrooxy Compounds with Different Molecular Structures on the Rumen Methanogenesis, Metabolic Profile, and Methanogenic Community.

PubMed

Jin, Wei; Meng, Zhenxiang; Wang, Jing; Cheng, Yanfen; Zhu, Weiyun

2017-08-01

Rumen in vitro fermentation was used to evaluate the capacity of nitrooxy compounds to mitigate rumen methane production. The following three nitrooxy compounds, each with different molecular structures, were evaluated: 2,2-dimethyl-3-(nitrooxy) propanoic (DNP), N-[2-(Nitrooxy)ethyl]-3-pyridinecarboxamide (NPD), and nitroglycerin (NG). All three compounds substantially decreased the total gas production, methane production, and the acetate:propionate ratio, while increasing hydrogen production. The growth of methanogens was specifically inhibited by all three compounds, without affecting the abundance of bacteria, anaerobic fungi, or protozoa. However, inhibition of methanogenesis required a much higher dose of DNP when compared to NPD or NG. Further investigations were conducted on NG to determine its effects on the methanogenic community. NG reduced the relative abundance of Methanomassiliicoccales, while increasing the relative abundance of Methanobrevibacter and Methanosphaera. Overall, the results suggested that all three of these nitrooxy compounds could specifically inhibit rumen methanogenesis, but NPD and NG were much more efficient than DNP at rumen methane mitigation.

Regulating emission of air pollutants for near-term relief from global warming

NASA Astrophysics Data System (ADS)

Ramanathan, V.; Xu, Y.

2011-12-01

The manmade greenhouse gases that are now blanketing the planet is thick enough to warm the system beyond the 20C threshold. Even with a targeted reduction in CO2 emission of 50% by 2050, we will still be adding more than 50 ppm of CO2 and add another 10C to the warming. Fortunately, there are still ways to contain the warming by reducing non-CO2 climate warmers (methane, lower atmosphere ozone, black carbon and HFCs), using available and field tested technologies. The major advantage of going for these 'low-hanging fruits' is that this approach will clean up the air and improve health and food security of south and east Asia, thus engaging developing nations more effectively in climate negotiations. These non-CO2 mitigation actions will have significant (beneficial) impacts on the chemistry, clouds and precipitation of the atmosphere and these have to be quantified adequately. For example, reducing black and organic carbon emissions (through cleaner cooking technologies in developing countries) will also lead to significant reductions in carbon monoxide, which is an ozone precursor. The institutional infrastructure for reducing non-CO2 climate warmers already exist and have a proven track record for successful climate mitigation.

Methane emission from sewers.

PubMed

Liu, Yiwen; Ni, Bing-Jie; Sharma, Keshab R; Yuan, Zhiguo

2015-08-15

Recent studies have shown that sewer systems produce and emit a significant amount of methane. Methanogens produce methane under anaerobic conditions in sewer biofilms and sediments, and the stratification of methanogens and sulfate-reducing bacteria may explain the simultaneous production of methane and sulfide in sewers. No significant methane sinks or methanotrophic activities have been identified in sewers to date. Therefore, most of the methane would be emitted at the interface between sewage and atmosphere in gravity sewers, pumping stations, and inlets of wastewater treatment plants, although oxidation of methane in the aeration basin of a wastewater treatment plant has been reported recently. Online measurements have also revealed highly dynamic temporal and spatial variations in methane production caused by factors such as hydraulic retention time, area-to-volume ratio, temperature, and concentration of organic matter in sewage. Both mechanistic and empirical models have been proposed to predict methane production in sewers. Due to the sensitivity of methanogens to environmental conditions, most of the chemicals effective in controlling sulfide in sewers also suppress or diminish methane production. In this paper, we review the recent studies on methane emission from sewers, including the production mechanisms, quantification, modeling, and mitigation. Copyright © 2015 Elsevier B.V. All rights reserved.

Greenhouse gas emissions from the waste sector in Argentina in business-as-usual and mitigation scenarios.

PubMed

Santalla, Estela; Córdoba, Verónica; Blanco, Gabriel

2013-08-01

The objective of this work was the application of 2006 Intergovernmental Panel on Climate Change (IPCC) Guidelines for the estimation of methane and nitrous oxide emissions from the waste sector in Argentina as a preliminary exercise for greenhouse gas (GHG) inventory development and to compare with previous inventories based on 1996 IPCC Guidelines. Emissions projections to 2030 were evaluated under two scenarios--business as usual (BAU), and mitigation--and the calculations were done by using the ad hoc developed IPCC software. According to local activity data, in the business-as-usual scenario, methane emissions from solid waste disposal will increase by 73% by 2030 with respect to the emissions of year 2000. In the mitigation scenario, based on the recorded trend of methane captured in landfills, a decrease of 50% from the BAU scenario should be achieved by 2030. In the BAU scenario, GHG emissions from domestic wastewater will increase 63% from 2000 to 2030. Methane emissions from industrial wastewater, calculated from activity data of dairy, swine, slaughterhouse, citric, sugar, and wine sectors, will increase by 58% from 2000 to 2030 while methane emissions from domestic will increase 74% in the same period. Results show that GHG emissions calculated from 2006 IPCC Guidelines resulted in lower levels than those reported in previous national inventories for solid waste disposal and domestic wastewater categories, while levels were 18% higher for industrial wastewater. The implementation of the 2006 IPCC Guidelines for National Greenhouse Inventories is now considering by the UNFCCC for non-Annex I countries in order to enhance the compilation of inventories based on comparable good practice methods. This work constitutes the first GHG emissions estimation from the waste sector of Argentina applying the 2006 IPCC Guidelines and the ad doc developed software. It will contribute to identifying the main differences between the models applied in the estimation of methane emissions on the key categories of waste emission sources and to comparing results with previous inventories based on 1996 IPCC Guidelines.

Mitigating ammonia inhibition of thermophilic anaerobic treatment of digested piggery wastewater: use of pH reduction, zeolite, biomass and humic acid.

PubMed

Ho, L; Ho, G

2012-09-15

High free ammonia released during anaerobic digestion of livestock wastes is widely known to inhibit methanogenic microorganisms and result in low methane production. This was encountered during our earlier thermophilic semi-continuously fed continuously-stirred tank reactor (CSTR) treatment of piggery wastewater. This study explored chemical and biological means to mitigate ammonia inhibition on thermophilic anaerobic treatment of piggery wastewater with the aim to increase organic volatile carbon reduction and methane production. A series of thermophilic anaerobic batch experiments were conducted on the digested piggery effluent to investigate the effects of pH reduction (pH 8.3 to 7.5, 7.0 and 6.5) and additions of biomass (10% v/v and 19% v/v anaerobic digested piggery biomass and aerobic-anaerobic digested municipal biomass), natural zeolite (10, 15 and 20 g/L) and humic acid (1, 5 and 10 g/L) on methane production at 55 °C for 9-11 days. Reduction of the wastewater pH from its initial pH of 8.3 to 6.5 produced the greatest stimulation of methane production (3.4 fold) coupled with reductions in free ammonia (38 fold) and total volatile fatty acids (58% TVFA), particularly acetate and propionate. Addition of 10-20 g/L zeolite to piggery wastewater with and without pH reduction to 6.5 further enhanced total VFA reduction and methane production over their respective controls, with 20 g/L zeolite producing the highest enhancement effect despite the ammonia-nitrogen concentrations of the treated wastewaters remaining high. Without pH reduction, zeolite concentration up to 20 g/L was required to achieve comparable methane enhancement as the pH-reduced wastewater at pH 6.5. Although biomass (10% v/v piggery and municipal wastes) and low humic acid (1 and 5 g/L) additions enhanced total VFA reduction and methane production, they elevated the residual effluent total COD concentrations over the control wastewaters (pH-unadjusted and pH-reduced) unlike zeolite treatment. The outcomes from these batch experiments support the use of pH reduction to 6.5 and zeolite treatment (10-20 g/L) as effective strategies to mitigate ammonia inhibition of the thermophilic anaerobic treatment of piggery wastewater. Copyright © 2012 Elsevier Ltd. All rights reserved.

Application of harmonic detection technology in methane telemetry

NASA Astrophysics Data System (ADS)

Huo, Yuehua; Fan, Weiqiang

2017-08-01

Methane telemetry plays a vital role in ensuring the safe production of coal mines and monitoring the leakage of natural gas pipelines. Harmonic detection is the key technology of methane telemetry accuracy and sensitivity, but the current telemetry distance is short, the relationship between different modulation parameters is complex, and the harmonic signal is affected by noise interference. These factors seriously affect the development of harmonic detection technology. In this paper, the principle of methane telemetry based on harmonic detection technology is introduced. The present situation and characteristics of harmonic detection technology are expounded. The problems existing in harmonic detection are analyzed. Finally, the future development trend is discussed.

Mitigation of methane emissions in cities: How new measurements and partnerships can contribute to emissions reduction strategies

DOE PAGES

Hopkins, Francesca M.; Ehleringer, James R.; Bush, Susan E.; ...

2016-09-10

Cities generate 70% of anthropogenic greenhouse gas emissions, a fraction that is grow-ing with global urbanization. While cities play an important role in climate change mitigation, there has been little focus on reducing urban methane (CH4) emissions. Here, we develop a conceptual framework for CH 4 mitigation in cities by describing emission processes, the role of measurements, and a need for new institutional partnerships. Urban CH 4 emissions are likely to grow with expanding use of natural gas and organic waste disposal systems in growing population centers; however, we currently lack the ability to quantify this increase. We also lackmore » systematic knowledge of the relative contribution of these distinct source sectors on emissions. We present new observations from four North American cities to demonstrate that CH4 emissions vary in magnitude and sector from city to city and hence require different mitigation strategies. Detections of fugitive emissions from these systems suggest that current mitiga- tion approaches are absent or ineffective. These findings illustrate that tackling urban CH 4 emissions will require research efforts to identify mitigation targets, develop and implement new mitigation strategies, and monitor atmospheric CH 4 levels to ensure the success of mitigation efforts. This research will require a variety of techniques to achieve these objectives and should be deployed in cities globally. In conclusion, we suggest that metropolitan scale partnerships may effectively coordinate systematic measurements and actions focused on emission reduction goals.« less

Mitigation of methane emissions in cities: How new measurements and partnerships can contribute to emissions reduction strategies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hopkins, Francesca M.; Ehleringer, James R.; Bush, Susan E.

Cities generate 70% of anthropogenic greenhouse gas emissions, a fraction that is grow-ing with global urbanization. While cities play an important role in climate change mitigation, there has been little focus on reducing urban methane (CH4) emissions. Here, we develop a conceptual framework for CH 4 mitigation in cities by describing emission processes, the role of measurements, and a need for new institutional partnerships. Urban CH 4 emissions are likely to grow with expanding use of natural gas and organic waste disposal systems in growing population centers; however, we currently lack the ability to quantify this increase. We also lackmore » systematic knowledge of the relative contribution of these distinct source sectors on emissions. We present new observations from four North American cities to demonstrate that CH4 emissions vary in magnitude and sector from city to city and hence require different mitigation strategies. Detections of fugitive emissions from these systems suggest that current mitiga- tion approaches are absent or ineffective. These findings illustrate that tackling urban CH 4 emissions will require research efforts to identify mitigation targets, develop and implement new mitigation strategies, and monitor atmospheric CH 4 levels to ensure the success of mitigation efforts. This research will require a variety of techniques to achieve these objectives and should be deployed in cities globally. In conclusion, we suggest that metropolitan scale partnerships may effectively coordinate systematic measurements and actions focused on emission reduction goals.« less

Development of a vaccine to mitigate greenhouse gas emissions in agriculture: vaccination of sheep with methanogen fractions induces antibodies that block methane production in vitro.

PubMed

Wedlock, D N; Pedersen, G; Denis, M; Dey, D; Janssen, P H; Buddle, B M

2010-02-01

To develop an understanding of the immune responses of ruminants to methanogens, and to provide proof of a concept that harnessing the immune system of ruminants is a potentially viable approach to mitigate greenhouse gas emissions from agriculture. Four subcellular fractions, namely cytoplasmic, two cell-wall preparations, and cell wall-derived proteins were prepared from Methanobrevibacter ruminantium M1. Twenty sheep (10 months of age) were vaccinated with these fractions or with whole cells (n=4 per group). Sheep were re-vaccinated once after 3 weeks, and antibody responses to M. ruminantium M1 antigens in sera and saliva measured using ELISA at 2 weeks after the second vaccination. Antigens recognised by the antisera were visualised using Western blotting. The antisera were tested in vitro for their impact on M. ruminantium M1, measuring the effect on cell growth, methane production, and ability to induce agglutination. Basal levels (pre-vaccination) of antibodies against M. ruminantium M1 antigens were low. Vaccination with the antigenic fractions induced strong antibody responses in serum. Both IgG and IgA responses to methanogen antigens were detected in saliva following vaccination. Western blot analysis of the antisera indicated reactivity of antibodies, and a wide range of proteins was present in the different methanogen fractions. Antisera against the various fractions agglutinated methanogens in an in-vitro assay. In addition, these antisera decreased the growth of a pure culture of a methanogen and production of methane in vitro. Antigens from methanogens are immunogenic in ruminants, and antisera from sheep vaccinated with fractions of methanogens have a significant impact on these organisms, inducing cell agglutination, and decreasing growth of methanogens and production of methane. Only antisera to selected methanogen fractions were able to achieve these effects. The results demonstrate the feasibility of a vaccination strategy to mitigate emission of methane.

Application of methane fermentation technology into organic wastes in closed agricultural system

NASA Astrophysics Data System (ADS)

Endo, Ryosuke; Kitaya, Yoshiaki

Sustainable and recycling-based systems are required in space agriculture which takes place in an enclosed environment. Methane fermentation is one of the most major biomass conversion technologies, because (1) it provides a renewable energy source as biogas including methane, suitable for energy production, (2) the nutrient-rich solids left after digestion can be used as compost for agriculture. In this study, the effect of the application of methane fermentation technology into space agriculture on the material and energy cycle was investigated.

Global Emissions of Nitrous Oxide: Key Source Sectors, their Future Activities and Technical Opportunities for Emission Reduction

NASA Astrophysics Data System (ADS)

Winiwarter, W.; Höglund-Isaksson, L.; Klimont, Z.; Schöpp, W.; Amann, M.

2017-12-01

Nitrous oxide originates primarily from natural biogeochemical processes, but its atmospheric concentrations have been strongly affected by human activities. According to IPCC, it is the third largest contributor to the anthropogenic greenhouse gas emissions (after carbon dioxide and methane). Deep decarbonization scenarios, which are able to constrain global temperature increase within 1.5°C, require strategies to cut methane and nitrous oxide emissions on top of phasing out carbon dioxide emissions. Employing the Greenhouse gas and Air pollution INteractions and Synergies (GAINS) model, we have estimated global emissions of nitrous oxide until 2050. Using explicitly defined emission reduction technologies we demonstrate that, by 2030, about 26% ± 9% of the emissions can be avoided assuming full implementation of currently existing reduction technologies. Nearly a quarter of this mitigation can be achieved at marginal costs lower than 10 Euro/t CO2-eq with the chemical industry sector offering important reductions. Overall, the largest emitter of nitrous oxide, agriculture, also provides the largest emission abatement potentials. Emission reduction may be achieved by precision farming methods (variable rate technology) as well as by agrochemistry (nitrification inhibitors). Regionally, the largest emission reductions are achievable where intensive agriculture and industry are prevalent (production and application of mineral fertilizers): Centrally Planned Asia including China, North and Latin America, and South Asia including India. Further deep cuts in nitrous oxide emissions will require extending reduction efforts beyond strictly technological solutions, i.e., considering behavioral changes, including widespread adoption of "healthy diets" minimizing excess protein consumption.

The Genome Sequence of the Rumen Methanogen Methanobrevibacter ruminantium Reveals New Possibilities for Controlling Ruminant Methane Emissions

PubMed Central

Leahy, Sinead C.; Kelly, William J.; Altermann, Eric; Ronimus, Ron S.; Yeoman, Carl J.; Pacheco, Diana M.; Li, Dong; Kong, Zhanhao; McTavish, Sharla; Sang, Carrie; Lambie, Suzanne C.; Janssen, Peter H.; Dey, Debjit; Attwood, Graeme T.

2010-01-01

Background Methane (CH4) is a potent greenhouse gas (GHG), having a global warming potential 21 times that of carbon dioxide (CO2). Methane emissions from agriculture represent around 40% of the emissions produced by human-related activities, the single largest source being enteric fermentation, mainly in ruminant livestock. Technologies to reduce these emissions are lacking. Ruminant methane is formed by the action of methanogenic archaea typified by Methanobrevibacter ruminantium, which is present in ruminants fed a wide variety of diets worldwide. To gain more insight into the lifestyle of a rumen methanogen, and to identify genes and proteins that can be targeted to reduce methane production, we have sequenced the 2.93 Mb genome of M. ruminantium M1, the first rumen methanogen genome to be completed. Methodology/Principal Findings The M1 genome was sequenced, annotated and subjected to comparative genomic and metabolic pathway analyses. Conserved and methanogen-specific gene sets suitable as targets for vaccine development or chemogenomic-based inhibition of rumen methanogens were identified. The feasibility of using a synthetic peptide-directed vaccinology approach to target epitopes of methanogen surface proteins was demonstrated. A prophage genome was described and its lytic enzyme, endoisopeptidase PeiR, was shown to lyse M1 cells in pure culture. A predicted stimulation of M1 growth by alcohols was demonstrated and microarray analyses indicated up-regulation of methanogenesis genes during co-culture with a hydrogen (H2) producing rumen bacterium. We also report the discovery of non-ribosomal peptide synthetases in M. ruminantium M1, the first reported in archaeal species. Conclusions/Significance The M1 genome sequence provides new insights into the lifestyle and cellular processes of this important rumen methanogen. It also defines vaccine and chemogenomic targets for broad inhibition of rumen methanogens and represents a significant contribution to worldwide efforts to mitigate ruminant methane emissions and reduce production of anthropogenic greenhouse gases. PMID:20126622

Methane mitigation with corn oil and calcium sulfate, responses on whole animal energy and nitrogen balance in dairy cattle consuming reduced-fat distillers grains plus solubles

USDA-ARS?s Scientific Manuscript database

Addition of fat and calcium sulfate to diets fed to ruminants has been shown to reduce methane production, but these factors have not shown effects on energy balance. A study using 16 multiparous (8 Holstein and 8 Jersey) (78 ± 15 DIM) (mean ± SD) lactating dairy cows was conducted to determine how ...

Mapping methane emissions using the airborne imaging spectrometer AVIRIS-NG

NASA Astrophysics Data System (ADS)

Thorpe, A. K.; Frankenberg, C.; Thompson, D. R.; Duren, R. M.; Bue, B. D.; Green, R. O.

2017-12-01

The next generation Airborne Visible/Infrared Imaging Spectrometer (AVIRIS-NG) has been used to survey large regions and map methane plumes with unambiguous identification of emission source locations. This capability is aided by real time detection and geolocation of gas plumes, permitting adaptive surveys and communication to ground teams for rapid follow up. We present results from AVIRIS-NG flight campaigns in Colorado, New Mexico, and California. Hundreds of plumes were observed, reflecting emissions from the energy sector that include hydraulic fracturing, gas processing plants, tanks, pumpjacks, and pipeline leaks. In some cases, plumes observed by AVIRIS-NG resulted in mitigation. Additional examples will be shown for methane from dairy lagoons, landfills, natural emissions, as well as carbon dioxide from power plants and refineries. We describe the unique capabilities of airborne imaging spectrometers to augment other measurement techniques by efficiently surveying key regions for methane point sources and supporting timely assessment and mitigation. We summarize the outlook for near- and longer-term monitoring capabilities including future satellite systems. Figure caption. AVIRIS-NG true color image subset with superimposed methane plume showing retrieved gas concentrations. Plume extends 200 m downwind of the southern edge of the well pad. Google Earth imagery with finer spatial resolution is also included (red box), indicating that tanks in the inset scene as the source of emissions. Five wells are located at the center of this well pad and all use horizontal drilling to produce mostly natural gas.

Performance Evaluation and Dissolved Oxygen Effect in Deep-bed Denitrification Filter: a Full-scale Plant Case Study

NASA Astrophysics Data System (ADS)

Hu, Xiang; Hu, Jie; Wu, Ke; Hou, Hongxun

2018-01-01

The aims of this study were twofold. Firstly, the denitrificaion performance in deep-bed denitrificaiton filter (DBDF), serving as the advanced total nitrogen (TN) and total phosphorus (TP) removal technology, was evaluated. Secondly, the effect of dissolved oxygen (DO) into the DBDF on both the denitrificaion performance and the external carbon source addition was investigated. The operational results over eight months demonstrated good TN removal efficiency (87.8%) in the studied full-scale plant, in which 70.7% and 17.1% of TN were removed in the pre-denitrifation in oxidation ditch and post-denitrifation in DBDF, respectively. The DO concentration was inversely related to both the external carbon source dosage and the nitrate removed in DBDF. A dose of 3.60Kg methane (97%) was required to remove 1Kg nitrate, with approximately 26.2% of methane dosed was depleted by the DO in DBDF influent. It is suggested to take some measures to eliminate or mitigate the waterfall reoxygenation at process configurations before the DBDF, which is expected to save the cost of external carbon source.

Does Dietary Mitigation of Enteric Methane Production Affect Rumen Function and Animal Productivity in Dairy Cows?

PubMed Central

Veneman, Jolien B.; Muetzel, Stefan; Hart, Kenton J.; Faulkner, Catherine L.; Moorby, Jon M.; Perdok, Hink B.; Newbold, Charles J.

2015-01-01

It has been suggested that the rumen microbiome and rumen function might be disrupted if methane production in the rumen is decreased. Furthermore concerns have been voiced that geography and management might influence the underlying microbial population and hence the response of the rumen to mitigation strategies. Here we report the effect of the dietary additives: linseed oil and nitrate on methane emissions, rumen fermentation, and the rumen microbiome in two experiments from New Zealand (Dairy 1) and the UK (Dairy 2). Dairy 1 was a randomized block design with 18 multiparous lactating cows. Dairy 2 was a complete replicated 3 x 3 Latin Square using 6 rumen cannulated, lactating dairy cows. Treatments consisted of a control total mixed ration (TMR), supplementation with linseed oil (4% of feed DM) and supplementation with nitrate (2% of feed DM) in both experiments. Methane emissions were measured in open circuit respiration chambers and rumen samples were analyzed for rumen fermentation parameters and microbial population structure using qPCR and next generation sequencing (NGS). Supplementation with nitrate, but not linseed oil, decreased methane yield (g/kg DMI; P<0.02) and increased hydrogen (P<0.03) emissions in both experiments. Furthermore, the effect of nitrate on gaseous emissions was accompanied by an increased rumen acetate to propionate ratio and consistent changes in the rumen microbial populations including a decreased abundance of the main genus Prevotella and a decrease in archaeal mcrA (log10 copies/ g rumen DM content). These results demonstrate that methane emissions can be significantly decreased with nitrate supplementation with only minor, but consistent, effects on the rumen microbial population and its function, with no evidence that the response to dietary additives differed due to geography and different underlying microbial populations. PMID:26509835

Does Dietary Mitigation of Enteric Methane Production Affect Rumen Function and Animal Productivity in Dairy Cows?

PubMed

Veneman, Jolien B; Muetzel, Stefan; Hart, Kenton J; Faulkner, Catherine L; Moorby, Jon M; Perdok, Hink B; Newbold, Charles J

2015-01-01

It has been suggested that the rumen microbiome and rumen function might be disrupted if methane production in the rumen is decreased. Furthermore concerns have been voiced that geography and management might influence the underlying microbial population and hence the response of the rumen to mitigation strategies. Here we report the effect of the dietary additives: linseed oil and nitrate on methane emissions, rumen fermentation, and the rumen microbiome in two experiments from New Zealand (Dairy 1) and the UK (Dairy 2). Dairy 1 was a randomized block design with 18 multiparous lactating cows. Dairy 2 was a complete replicated 3 x 3 Latin Square using 6 rumen cannulated, lactating dairy cows. Treatments consisted of a control total mixed ration (TMR), supplementation with linseed oil (4% of feed DM) and supplementation with nitrate (2% of feed DM) in both experiments. Methane emissions were measured in open circuit respiration chambers and rumen samples were analyzed for rumen fermentation parameters and microbial population structure using qPCR and next generation sequencing (NGS). Supplementation with nitrate, but not linseed oil, decreased methane yield (g/kg DMI; P<0.02) and increased hydrogen (P<0.03) emissions in both experiments. Furthermore, the effect of nitrate on gaseous emissions was accompanied by an increased rumen acetate to propionate ratio and consistent changes in the rumen microbial populations including a decreased abundance of the main genus Prevotella and a decrease in archaeal mcrA (log10 copies/g rumen DM content). These results demonstrate that methane emissions can be significantly decreased with nitrate supplementation with only minor, but consistent, effects on the rumen microbial population and its function, with no evidence that the response to dietary additives differed due to geography and different underlying microbial populations.

Systems level insights into alternate methane cycling modes in a freshwater lake via community transcriptomics, metabolomics and nano-SIMS analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lidstrom, Mary E.; Chistoserdova, Ludmila; Kalyuzhnaya, Marina G.

2014-08-07

The research conducted as part of this project contributes significantly to the understanding of the microbes and their activities involved in methane metabolism in freshwater lake sediments and in the environment in a more global sense. Significant new insights have been gained into the identity of the species that are most active in methane oxidation. New concepts have been developed based on the new data on how these organisms metabolize methane, impacting not only environmental microbiology but also biotechnology, including biotechnology of next generation biofuels. Novel approaches have been developed for studying functional microbial communities, via holistic approaches, such asmore » metagenomics, metatrancriptomics and metabolite analysis. As a result, a novel outlook has been obtained at how such communities operate in nature. Understanding methane-oxidizing communities in lakes and other environments is of significant benefit to the public, in terms of methane emission mitigation and in terms of potential biotechnological applications.« less

Low-temperature upgrading of low-calorific biogas for CO2 mitigation using DBD-catalyst hybrid reactor

NASA Astrophysics Data System (ADS)

Nozaki, Tomohiro; Tsukijihara, Hiroyuki; Fukui, Wataru; Okazaki, Ken

2006-10-01

Although huge amounts of biogas, which consists of 20-60% of CH4 in CO2/N2, can be obtained from landfills, coal mines, and agricultural residues, most of them are simply flared and wasted: because global warming potential of biogas is 5-15 times as potent as CO2. Poor combustibility of such biogas makes it difficult to utilize in conventional energy system. The purpose of this project is to promote the profitable recovery of methane from poor biogas via non-thermal plasma technology. We propose low-temperature steam reforming of biogas using DBD generated in catalyst beds. Methane is partially converted into hydrogen, and then fed into internal combustion engines for improved ignition stability as well as efficient operation. Low-temperature steam reforming is beneficial because exhaust gas from an engine can be used to activate catalyst beds. Space velocity (3600-15000 hr-1), reaction temperature (300-650^oC), and energy cost (30-150 kJ per mol CH4) have been investigated with simulated biogas (20-60% CH4 in mixtures of CO2/N2). The DBD enhances reaction rate of CH4 by a factor of ten at given catalyst temperatures, which is a rate-determining step of methane steam reforming, while species concentration of upgraded biogas was governed by thermodynamic equilibrium in the presence of catalyst.

Biologically derived fertilizer: A multifaceted bio-tool in methane mitigation.

PubMed

Singh, Jay Shankar; Strong, P J

2016-02-01

Methane emissions are affected by agricultural practices. Agriculture has increased in scale and intensity because of greater food, feed and energy demands. The application of chemical fertilizers in agriculture, particularly in paddy fields, has contributed to increased atmospheric methane emissions. Using organic fertilizers may improve crop yields and the methane sink potential within agricultural systems, which may be further improved when combined with beneficial microbes (i.e. biofertilizers) that improve the activity of methane oxidizing bacteria such as methanotrophs. Biofertilizers may be an effective tool for agriculture that is environmentally beneficial compared to conventional inorganic fertilizers. This review highlights and discusses the interplay between ammonia and methane oxidizing bacteria, the potential interactions of microbial communities with microbially-enriched organic amendments and the possible role of these biofertilizers in augmenting the methane sink potential of soils. It is suggested that biofertilizer applications should not only be investigated in terms of sustainable agriculture productivity and environmental management, but also in terms of their effects on methanogen and methanotroph populations. Copyright © 2015 Elsevier Inc. All rights reserved.

Measurement and mitigation of methane emissions from beef cattle in tropical grazing systems: a perspective from Australia and Brazil.

PubMed

Berndt, A; Tomkins, N W

2013-06-01

The growing global demand for food of animal origin will be the incentive for countries such as Australia and Brazil to increase their beef production and international exports. This increased supply of beef is expected to occur primarily through on-farm productivity increases. The strategies for reducing resultant greenhouse gas (GHG) emissions should be evaluated in the context of the production system and should encompass a broader analysis, which would include the emissions of methane (CH4) and nitrous oxide (N2O) and carbon sequestration. This paper provides an insight into CH4 measurement techniques applicable to grazing environments and proposed mitigation strategies, with relevance to the production systems that are predominant in grazing systems of Australia and Brazil. Research and technology investment in both Australia and Brazil is aimed at developing measurement techniques and increasing the efficiency of cattle production by improving herd genetics, utilization of the seasonal feed-base and reducing the proportion of metabolizable energy lost as CH4. Concerted efforts in these areas can be expected to reduce the number of unproductive animals, reduce age at slaughter and inevitably reduce emission intensity (EI) from beef production systems. Improving efficiency of livestock production systems in tropical grazing systems for Australia and Brazil will be based on cultivated and existing native pastures and the use of additives and by-products from other agricultural sectors. This approach spares grain-based feed reserves typically used for human consumption, but potentially incurs a heavier EI than current intensive feeding systems. The determination of GHG emissions and the value of mitigation outcomes for entire beef production systems in the extensive grazing systems is complex and require a multidisciplinary approach. It is fortunate that governments in both Australia and Brazil are supporting ongoing research activities. Nevertheless, to achieve an outcome that feeds a growing population while reducing emissions on a global scale continues to be a monumental challenge for ruminant nutritionists.

Upward revision of global fossil fuel methane emissions based on isotope database.

PubMed

Schwietzke, Stefan; Sherwood, Owen A; Bruhwiler, Lori M P; Miller, John B; Etiope, Giuseppe; Dlugokencky, Edward J; Michel, Sylvia Englund; Arling, Victoria A; Vaughn, Bruce H; White, James W C; Tans, Pieter P

2016-10-06

Methane has the second-largest global radiative forcing impact of anthropogenic greenhouse gases after carbon dioxide, but our understanding of the global atmospheric methane budget is incomplete. The global fossil fuel industry (production and usage of natural gas, oil and coal) is thought to contribute 15 to 22 per cent of methane emissions to the total atmospheric methane budget. However, questions remain regarding methane emission trends as a result of fossil fuel industrial activity and the contribution to total methane emissions of sources from the fossil fuel industry and from natural geological seepage, which are often co-located. Here we re-evaluate the global methane budget and the contribution of the fossil fuel industry to methane emissions based on long-term global methane and methane carbon isotope records. We compile the largest isotopic methane source signature database so far, including fossil fuel, microbial and biomass-burning methane emission sources. We find that total fossil fuel methane emissions (fossil fuel industry plus natural geological seepage) are not increasing over time, but are 60 to 110 per cent greater than current estimates owing to large revisions in isotope source signatures. We show that this is consistent with the observed global latitudinal methane gradient. After accounting for natural geological methane seepage, we find that methane emissions from natural gas, oil and coal production and their usage are 20 to 60 per cent greater than inventories. Our findings imply a greater potential for the fossil fuel industry to mitigate anthropogenic climate forcing, but we also find that methane emissions from natural gas as a fraction of production have declined from approximately 8 per cent to approximately 2 per cent over the past three decades.

Iron-mediated anaerobic oxidation of methane in brackish coastal sediments.

PubMed

Egger, Matthias; Rasigraf, Olivia; Sapart, Célia J; Jilbert, Tom; Jetten, Mike S M; Röckmann, Thomas; van der Veen, Carina; Bândă, Narcisa; Kartal, Boran; Ettwig, Katharina F; Slomp, Caroline P

2015-01-06

Methane is a powerful greenhouse gas and its biological conversion in marine sediments, largely controlled by anaerobic oxidation of methane (AOM), is a crucial part of the global carbon cycle. However, little is known about the role of iron oxides as an oxidant for AOM. Here we provide the first field evidence for iron-dependent AOM in brackish coastal surface sediments and show that methane produced in Bothnian Sea sediments is oxidized in distinct zones of iron- and sulfate-dependent AOM. At our study site, anthropogenic eutrophication over recent decades has led to an upward migration of the sulfate/methane transition zone in the sediment. Abundant iron oxides and high dissolved ferrous iron indicate iron reduction in the methanogenic sediments below the newly established sulfate/methane transition. Laboratory incubation studies of these sediments strongly suggest that the in situ microbial community is capable of linking methane oxidation to iron oxide reduction. Eutrophication of coastal environments may therefore create geochemical conditions favorable for iron-mediated AOM and thus increase the relevance of iron-dependent methane oxidation in the future. Besides its role in mitigating methane emissions, iron-dependent AOM strongly impacts sedimentary iron cycling and related biogeochemical processes through the reduction of large quantities of iron oxides.

Quantifying, Assessing, and Mitigating Methane Emissions from Super-emitters in the Oil and Gas Supply Chain

NASA Astrophysics Data System (ADS)

Lyon, David Richard

Methane emissions from the oil and gas (O&G) supply chain reduce potential climate benefits of natural gas as a replacement for other fossil fuels that emit more carbon dioxide per energy produced. O&G facilities have skewed emission rate distributions with a small fraction of sites contributing the majority of emissions. Knowledge of the identity and cause of these high emission facilities, referred to as super-emitters or fat-tail sources, is critical for reducing supply chain emissions. This dissertation addresses the quantification of super-emitter emissions, assessment of their prevalence and relationship to site characteristics, and mitigation with continuous leak detection systems. Chapter 1 summarizes the state of the knowledge of O&G methane emissions. Chapter 2 constructs a spatially-resolved emission inventory to estimate total and O&G methane emissions in the Barnett Shale as part of a coordinated research campaign using multiple top-down and bottom-up methods to quantify emissions. The emission inventory accounts for super-emitters with two-phase Monte Carlo simulations that combine site measurements collected with two approaches: unbiased sampling and targeted sampling of super-emitters. More comprehensive activity data and the inclusion of super-emitters, which account for 19% of O&G emissions, produces a emission inventory that is not statistically different than top-down regional emission estimates. Chapter 3 describes a helicopter-based survey of over 8,000 well pads in seven basins with infrared optical gas imaging to assess high emission sources. Four percent of sites are observed to have high emissions with over 90% of observed sources from tanks. The occurrence of high emissions is weakly correlated to site parameters and the best statistical model explains only 14% of variance, which demonstrates that the occurrence of super-emitters is primarily stochastic. Chapter 4 presents a Gaussian dispersion model for optimizing the placement of continuous leak detection systems at three example well pads. The model demonstrates that large leaks can be detected quickly with first generation systems. Continuous leak detection can be used in the near future to cost-effectively mitigate methane emissions from O&G super-emitters.

Strategies to mitigate nitrous oxide emissions from herbivore production systems.

PubMed

Schils, R L M; Eriksen, J; Ledgard, S F; Vellinga, Th V; Kuikman, P J; Luo, J; Petersen, S O; Velthof, G L

2013-03-01

Herbivores are a significant source of nitrous oxide (N(2)O) emissions. They account for a large share of manure-related N(2)O emissions, as well as soil-related N(2)O emissions through the use of grazing land, and land for feed and forage production. It is widely acknowledged that mitigation measures are necessary to avoid an increase in N(2)O emissions while meeting the growing global food demand. The production and emissions of N(2)O are closely linked to the efficiency of nitrogen (N) transfer between the major components of a livestock system, that is, animal, manure, soil and crop. Therefore, mitigation options in this paper have been structured along these N pathways. Mitigation technologies involving diet-based intervention include lowering the CP content or increasing the condensed tannin content of the diet. Animal-related mitigation options also include breeding for improved N conversion and high animal productivity. The main soil-based mitigation measures include efficient use of fertilizer and manure, including the use of nitrification inhibitors. In pasture-based systems with animal housing facilities, reducing grazing time is an effective option to reduce N(2)O losses. Crop-based options comprise breeding efforts for increased N-use efficiency and the use of pastures with N(2)-fixing clover. It is important to recognize that all N(2)O mitigation options affect the N and carbon cycles of livestock systems. Therefore, care should be taken that reductions in N(2)O emissions are not offset by unwanted increases in ammonia, methane or carbon dioxide emissions. Despite the abundant availability of mitigation options, implementation in practice is still lagging. Actual implementation will only follow after increased awareness among farmers and greenhouse gases targeted policies. So far, reductions in N(2)O emissions that have been achieved are mostly a positive side effect of other N-targeted policies.

Herbage intake, methane emissions and animal performance of steers grazing dwarf elephant grass v. dwarf elephant grass and peanut pastures.

PubMed

Andrade, E A; Almeida, E X; Raupp, G T; Miguel, M F; de Liz, D M; Carvalho, P C F; Bayer, C; Ribeiro-Filho, H M N

2016-10-01

Management strategies for increasing ruminant legume consumption and mitigating methane emissions from tropical livestock production systems require further study. The aim of this work was to evaluate the herbage intake, animal performance and enteric methane emissions of cattle grazing dwarf elephant grass (DEG) (Pennisetum purpureum cv. BRS Kurumi) alone or DEG with peanut (Arachis pintoi cv. Amarillo). The experimental treatments were the following: DEG pastures receiving nitrogen fertilization (150 kg N/ha as ammonium nitrate) and DEG intercropped with peanut plus an adjacent area of peanut that was accessible to grazing animals for 5 h/day (from 0700 to 1200 h). The animals grazing legume pastures showed greater average daily gain and herbage intake, and shorter morning and total grazing times. Daily methane emissions were greater from the animals grazing legume pastures, whereas methane emissions per unit of herbage intake did not differ between treatments. Allowing animals access to an exclusive area of legumes in a tropical grass-pasture-based system can improve animal performance without increasing methane production per kg of dry matter intake.

Development of Multiwell-Plate Methods Using Pure Cultures of Methanogens To Identify New Inhibitors for Suppressing Ruminant Methane Emissions.

PubMed

Weimar, M R; Cheung, J; Dey, D; McSweeney, C; Morrison, M; Kobayashi, Y; Whitman, W B; Carbone, V; Schofield, L R; Ronimus, R S; Cook, G M

2017-08-01

Hydrogenotrophic methanogens typically require strictly anaerobic culturing conditions in glass tubes with overpressures of H 2 and CO 2 that are both time-consuming and costly. To increase the throughput for screening chemical compound libraries, 96-well microtiter plate methods for the growth of a marine (environmental) methanogen Methanococcus maripaludis strain S2 and the rumen methanogen Methanobrevibacter species AbM4 were developed. A number of key parameters (inoculum size, reducing agents for medium preparation, assay duration, inhibitor solvents, and culture volume) were optimized to achieve robust and reproducible growth in a high-throughput microtiter plate format. The method was validated using published methanogen inhibitors and statistically assessed for sensitivity and reproducibility. The Sigma-Aldrich LOPAC library containing 1,280 pharmacologically active compounds and an in-house natural product library (120 compounds) were screened against M. maripaludis as a proof of utility. This screen identified a number of bioactive compounds, and MIC values were confirmed for some of them against M. maripaludis and M. AbM4. The developed method provides a significant increase in throughput for screening compound libraries and can now be used to screen larger compound libraries to discover novel methanogen-specific inhibitors for the mitigation of ruminant methane emissions. IMPORTANCE Methane emissions from ruminants are a significant contributor to global greenhouse gas emissions, and new technologies are required to control emissions in the agriculture technology (agritech) sector. The discovery of small-molecule inhibitors of methanogens using high-throughput phenotypic (growth) screening against compound libraries (synthetic and natural products) is an attractive avenue. However, phenotypic inhibitor screening is currently hindered by our inability to grow methanogens in a high-throughput format. We have developed, optimized, and validated a high-throughput 96-well microtiter plate assay for growing environmental and rumen methanogens. Using this platform, we identified several new inhibitors of methanogen growth, demonstrating the utility of this approach to fast track the development of methanogen-specific inhibitors for controlling ruminant methane emissions. Copyright © 2017 American Society for Microbiology.

Production of methane-rich syngas from hydrocarbon fuels using multi-functional catalyst/capture agent

DOEpatents

Siefert, Nicholas S; Shekhawat, Dushyant; Berry, David A; Surdoval, Wayne A

2014-12-30

The disclosure provides a gasification process for the production of a methane-rich syngas at temperatures exceeding 700.degree. C. through the use of an alkali hydroxide MOH, using a gasification mixture comprised of at least 0.25 moles and less than 2 moles of water for each mole of carbon, and at least 0.15 moles and less than 2 moles of alkali hydroxide MOH for each mole of carbon. These relative amounts allow the production of a methane-rich syngas at temperatures exceeding 700.degree. C. by enabling a series of reactions which generate H.sub.2 and CH.sub.4, and mitigate the reforming of methane. The process provides a methane-rich syngas comprised of roughly 20% (dry molar percentage) CH.sub.4 at temperatures above 700.degree. C., and may effectively operate within an IGFC cycle at reactor temperatures between 700-900.degree. C. and pressures in excess of 10 atmospheres.

Methane-rich syngas production from hydrocarbon fuels using multi-functional catalyst/capture agent

DOEpatents

Siefert, Nicholas S.; Shekhawat, Dushyant; Berry, David A.; Surdoval, Wayne A.

2017-02-07

The disclosure provides a gasification process for the production of a methane-rich syngas at temperatures exceeding 400.degree. C. through the use of an alkali hydroxide MOH, using a gasification mixture comprised of at least 0.25 moles and less than 2 moles of water for each mole of carbon, and at least 0.15 moles and less than 2 moles of alkali hydroxide MOH for each mole of carbon. These relative amounts allow the production of a methane-rich syngas at temperatures exceeding 400.degree. C. by enabling a series of reactions which generate H.sub.2 and CH.sub.4, and mitigate the reforming of methane. The process provides a methane-rich syngas comprised of roughly 20% (dry molar percentage) CH.sub.4 at temperatures above 400.degree. C., and may effectively operate within an IGFC cycle at reactor temperatures between 400-900.degree. C. and pressures in excess of 10 atmospheres.

Evaluation of the impact of organic material on the anaerobic methane and ammonium removal in a membrane aerated biofilm reactor (MABR) based on the multispecies biofilm modeling.

PubMed

Wu, Jun; Zhang, Yue

2017-01-01

The simultaneous nitrogen and methane removal by the combined nitritation, anaerobic ammonium oxidation (anammox), and nitrite dependent anaerobic methane oxidation (n-damo) processes in the membrane aerated biofilm reactor (MABR) offers clear advantages in term of energy saving and greenhouse gas emission mitigation. The rejected water from sludge digestion usually contained high ammonium, COD, and dissolved methane. The impact of influent COD on the anaerobic methane and ammonium removal in an MABR was evaluated in the model based study. The results indicated that the influent COD did not reduce the methane and ammonium removal efficiency at C/N ratio (influent COD/NH 4 + -N) less than 0.1. At high C/N ratio, the oxygen transfer coefficient needed to be increased to achieve high methane and nitrogen removal. Substrate flux analysis indicated that heterotrophic denitrification in the outside layer of biofilm reduced the impact of influent COD. Heterotrophic growth needed to be limited at the outside layer by using NO 3 - as electron acceptor; otherwise, the heterotrophic bacteria would compete NO 2 - and space with anammox and n-damo bacteria in the inner layers and reduce the nitrogen and methane removal efficiency.

Valuing the Ozone-Related Health Benefits of Methane Emission Controls

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sarofim, Marcus C.; Waldhoff, Stephanie T.; Anenberg, Susan C.

Methane is a greenhouse gas that oxidizes to form ground-level ozone, itself a greenhouse gas and a health-harmful air pollutant. Reducing methane emissions will both slow anthropogenic climate change and reduce ozone-related mortality. We estimate the benefits of reducing methane emissions anywhere in the world for ozone-related premature mortality globally and for eight geographic regions. Our methods are consistent with those used by the U.S. Government to estimate the Social Cost of Carbon (SCC). We find that the global short- and long-term premature mortality benefits due to reduced ozone production from methane mitigation are (2011)$790 and $1775 per tonne methane,more » respectively. These correspond to approximately 70% and 150% of the valuation of methane’s global climate impacts using the SCC after extrapolating from carbon dioxide to methane using Global Warming Potential (GWP) estimates. Results are most sensitive to the choice of VSL and increase for emission years further in the future. Regionally, most of the global mortality benefits accrue in Asia, but 10% accrue in the United States. This methodology can be used to assess the benefits of methane emission reductions anywhere in the world, including those achieved by national and multinational policies.« less

Atmospheric Gas Concentrations in the pre- and post-production Phases of an Unconventional Oil and Gas Recovery Operation at the MSEEL Test Site, West Virginia

NASA Astrophysics Data System (ADS)

Williams, J. P.; Reeder, M.; Pekney, N.; Osborne, J.; Risk, D. A.; McCawley, M.

2016-12-01

The Marcellus Shale Energy and Environment Laboratory (MSEEL) in West Virginia provides a unique opportunity in the field of unconventional energy research. By studying near-surface atmospheric chemistry over several phases of a hydraulic fracturing event, the project will help evaluate the impact of current practices, as well as new techniques and mitigation technologies. A total of 10 mobile surveys were conducted around the MSEEL site that contains 3 test wells (1 science well and 2 natural gas producing wells) and over several miles of nearby regional routes. Our surveying technique involved using a vehicle-mounted Los Gatos Research Ultraportable Methane/Acetylene Analyzer that provided geo-located measurements of methane (CH4) and carbon dioxide (CO2). The ratios of super-ambient concentrations of CO2 and CH4 were used to separate drilling- and fracturing-related observations from the natural background concentrations over the various well pad developmental stages. We found that regional background methane concentrations were elevated in all surveys, with a mean concentration of 3.21ppm (n = 99376), which simply reflected the mix of anthropogenic and natural CH4 sources in this riverine urban location. Over time and through successive stages of well development, we noted a progressive rise in the occurrence of enriched methane in the vicinity of the developed wells. While there was a moderate degree of variability over time, we did observe a higher occurrence of CH4-enriched observations during and after production began at the test site ( 25% of measurements within 500 meters of the test wells) compared to the baseline surveys (>10% of measurements). This change was expected, as we anticipated some level of increased emissions from the well pads as production began. However, we did not expect the rise to be so noticeable. The results of this study show that there is a statistically significant increase in the occurrence of enriched methane values in the vicinity of the well locations when we compare pre-production to post-production surveys, and that pre-existing methane sources in the immediate vicinity must be accounted for when assessing environmental impacts.

Sound management may sequester methane in grazed rangeland ecosystems

PubMed Central

Wang, Chengjie; Han, Guodong; Wang, Shiping; Zhai, Xiajie; Brown, Joel; Havstad, Kris M.; Ma, Xiuzhi; Wilkes, Andreas; Zhao, Mengli; Tang, Shiming; Zhou, Pei; Jiang, Yuanyuan; Lu, Tingting; Wang, Zhongwu; Li, Zhiguo

2014-01-01

Considering their contribution to global warming, the sources and sinks of methane (CH4) should be accounted when undertaking a greenhouse gas inventory for grazed rangeland ecosystems. The aim of this study was to evaluate the mitigation potential of current ecological management programs implemented in the main rangeland regions of China. The influences of rangeland improvement, utilization and livestock production on CH4 flux/emission were assessed to estimate CH4 reduction potential. Results indicate that the grazed rangeland ecosystem is currently a net source of atmospheric CH4. However, there is potential to convert the ecosystem to a net sink by improving management practices. Previous assessments of capacity for CH4 uptake in grazed rangeland ecosystems have not considered improved livestock management practices and thus underestimated potential for CH4 uptake. Optimal fertilization, rest and light grazing, and intensification of livestock management contribute mitigation potential significantly. PMID:24658176

Sound management may sequester methane in grazed rangeland ecosystems.

PubMed

Wang, Chengjie; Han, Guodong; Wang, Shiping; Zhai, Xiajie; Brown, Joel; Havstad, Kris M; Ma, Xiuzhi; Wilkes, Andreas; Zhao, Mengli; Tang, Shiming; Zhou, Pei; Jiang, Yuanyuan; Lu, Tingting; Wang, Zhongwu; Li, Zhiguo

2014-03-24

Considering their contribution to global warming, the sources and sinks of methane (CH4) should be accounted when undertaking a greenhouse gas inventory for grazed rangeland ecosystems. The aim of this study was to evaluate the mitigation potential of current ecological management programs implemented in the main rangeland regions of China. The influences of rangeland improvement, utilization and livestock production on CH4 flux/emission were assessed to estimate CH4 reduction potential. Results indicate that the grazed rangeland ecosystem is currently a net source of atmospheric CH4. However, there is potential to convert the ecosystem to a net sink by improving management practices. Previous assessments of capacity for CH4 uptake in grazed rangeland ecosystems have not considered improved livestock management practices and thus underestimated potential for CH4 uptake. Optimal fertilization, rest and light grazing, and intensification of livestock management contribute mitigation potential significantly.

Alternative technologies to steam-methane reforming

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tindall, B.M.; Crews, M.A.

1995-11-01

Steam-methane reforming (SMR) has been the conventional route for hydrogen and carbon monoxide production from natural gas feedstocks. However, several alternative technologies are currently finding favor for an increasing number of applications. The competing technologies include: steam-methane reforming combined with oxygen secondary reforming (SMR/O2R); autothermal reforming (ATR); thermal partial oxidation (POX). Each of these alternative technologies uses oxygen as a feedstock. Accordingly, if low-cost oxygen is available, they can be an attractive alternate to SMR with natural gas feedstocks. These technologies are composed technically and economically. The following conclusions can be drawn: (1) the SMR/O2R, ATR and POX technologies canmore » be attractive if low-cost oxygen is available; (2) for competing technologies, the H{sub 2}/CO product ratio is typically the most important process parameter; (3) for low methane slip, the SMR/O2R, ATR and POX technologies are favored; (4) for full CO{sub 2} recycle, POX is usually better than ATR; (5) relative to POX, the ATR is a nonlicensed technology that avoids third-party involvement; (6) economics of each technology are dependent on the conditions and requirements for each project and must be evaluated on a case-by-case basis.« less

An inhibitor persistently decreased enteric methane emission from dairy cows with no negative effect on milk production

PubMed Central

Hristov, Alexander N.; Oh, Joonpyo; Giallongo, Fabio; Frederick, Tyler W.; Harper, Michael T.; Weeks, Holley L.; Branco, Antonio F.; Moate, Peter J.; Deighton, Matthew H.; Williams, S. Richard O.; Kindermann, Maik; Duval, Stephane

2015-01-01

A quarter of all anthropogenic methane emissions in the United States are from enteric fermentation, primarily from ruminant livestock. This study was undertaken to test the effect of a methane inhibitor, 3-nitrooxypropanol (3NOP), on enteric methane emission in lactating Holstein cows. An experiment was conducted using 48 cows in a randomized block design with a 2-wk covariate period and a 12-wk data collection period. Feed intake, milk production, and fiber digestibility were not affected by the inhibitor. Milk protein and lactose yields were increased by 3NOP. Rumen methane emission was linearly decreased by 3NOP, averaging about 30% lower than the control. Methane emission per unit of feed dry matter intake or per unit of energy-corrected milk were also about 30% less for the 3NOP-treated cows. On average, the body weight gain of 3NOP-treated cows was 80% greater than control cows during the 12-wk experiment. The experiment demonstrated that the methane inhibitor 3NOP, applied at 40 to 80 mg/kg feed dry matter, decreased methane emissions from high-producing dairy cows by 30% and increased body weight gain without negatively affecting feed intake or milk production and composition. The inhibitory effect persisted over 12 wk of treatment, thus offering an effective methane mitigation practice for the livestock industries. PMID:26229078

Assessing the impact of rumen microbial communities on methane emissions and production traits in Holstein cows in a tropical climate.

PubMed

Cunha, Camila S; Veloso, Cristina M; Marcondes, Marcos I; Mantovani, Hilario C; Tomich, Thierry R; Pereira, Luiz Gustavo R; Ferreira, Matheus F L; Dill-McFarland, Kimberly A; Suen, Garret

2017-12-01

The evaluation of how the gut microbiota affects both methane emissions and animal production is necessary in order to achieve methane mitigation without production losses. Toward this goal, the aim of this study was to correlate the rumen microbial communities (bacteria, archaea, and fungi) of high (HP), medium (MP), and low milk producing (LP), as well as dry (DC), Holstein dairy cows in an actual tropical production system with methane emissions and animal production traits. Overall, DC cows emitted more methane, followed by MP, HP and LP cows, although HP and LP cow emissions were similar. Using next-generation sequencing, it was found that bacteria affiliated with Christensenellaceae, Mogibacteriaceae, S24-7, Butyrivibrio, Schwartzia, and Treponema were negatively correlated with methane emissions and showed positive correlations with digestible dry matter intake (dDMI) and digestible organic matter intake (dOMI). Similar findings were observed for archaea in the genus Methanosphaera. The bacterial groups Coriobacteriaceae, RFP12, and Clostridium were negatively correlated with methane, but did not correlate with dDMI and dOMI. For anaerobic fungal communities, no significant correlations with methane or animal production traits were found. Based on these findings, it is suggested that manipulation of the abundances of these microbial taxa may be useful for modulating methane emissions without negatively affecting animal production. Copyright © 2017 Elsevier GmbH. All rights reserved.

An inhibitor persistently decreased enteric methane emission from dairy cows with no negative effect on milk production.

PubMed

Hristov, Alexander N; Oh, Joonpyo; Giallongo, Fabio; Frederick, Tyler W; Harper, Michael T; Weeks, Holley L; Branco, Antonio F; Moate, Peter J; Deighton, Matthew H; Williams, S Richard O; Kindermann, Maik; Duval, Stephane

2015-08-25

A quarter of all anthropogenic methane emissions in the United States are from enteric fermentation, primarily from ruminant livestock. This study was undertaken to test the effect of a methane inhibitor, 3-nitrooxypropanol (3NOP), on enteric methane emission in lactating Holstein cows. An experiment was conducted using 48 cows in a randomized block design with a 2-wk covariate period and a 12-wk data collection period. Feed intake, milk production, and fiber digestibility were not affected by the inhibitor. Milk protein and lactose yields were increased by 3NOP. Rumen methane emission was linearly decreased by 3NOP, averaging about 30% lower than the control. Methane emission per unit of feed dry matter intake or per unit of energy-corrected milk were also about 30% less for the 3NOP-treated cows. On average, the body weight gain of 3NOP-treated cows was 80% greater than control cows during the 12-wk experiment. The experiment demonstrated that the methane inhibitor 3NOP, applied at 40 to 80 mg/kg feed dry matter, decreased methane emissions from high-producing dairy cows by 30% and increased body weight gain without negatively affecting feed intake or milk production and composition. The inhibitory effect persisted over 12 wk of treatment, thus offering an effective methane mitigation practice for the livestock industries.

Crop yield changes induced by emissions of individual climate-altering pollutants

NASA Astrophysics Data System (ADS)

Shindell, Drew T.

2016-08-01

Climate change damages agriculture, causing deteriorating food security and increased malnutrition. Many studies have examined the role of distinct physical processes, but impacts have not been previously attributed to individual pollutants. Using a simple model incorporating process-level results from detailed models, here I show that although carbon dioxide (CO2) is the largest driver of climate change, other drivers appear to dominate agricultural yield changes. I calculate that anthropogenic emissions to date have decreased global agricultural yields by 9.5 ± 3.0%, with roughly 93% stemming from non-CO2 emissions, including methane (-5.2 ± 1.7%) and halocarbons (-1.4 ± 0.4%). The differing impacts stem from atmospheric composition responses: CO2 fertilizes crops, offsetting much of the loss induced by warming; halocarbons do not fertilize; methane leads to minimal fertilization but increases surface ozone which augments warming-induced losses. By the end of the century, strong CO2 mitigation improves agricultural yields by ˜3 ± 5%. In contrast, strong methane and hydrofluorocarbon mitigation improve yields by ˜16 ± 5% and ˜5 ± 4%, respectively. These are the first quantitative analyses to include climate, CO2 and ozone simultaneously, and hence, additional studies would be valuable. Nonetheless, as policy makers have leverage over pollutant emissions rather than isolated processes, the perspective presented here may be more useful for decision making than that in the prior work upon which this study builds. The results suggest that policies should target a broad portfolio of pollutant emissions in order to optimize mitigation of societal damages.

The use of direct-fed microbials for mitigation of ruminant methane emissions: a review.

PubMed

Jeyanathan, J; Martin, C; Morgavi, D P

2014-02-01

Concerns about the environmental effect and the economic burden of methane (CH4) emissions from ruminants are driving the search for ways to mitigate rumen methanogenesis. The use of direct-fed microbials (DFM) is one possible option to decrease CH4 emission from ruminants. Direct-fed microbials are already used in ruminants mainly to increase productivity and to improve health, and are readily accepted by producers and consumers alike. However, studies on the use of DFM as rumen CH4 mitigants are scarce. A few studies using Saccharomyces cerevisiae have shown a CH4-decreasing effect but, to date, there has not been a systematic exploration of DFM as modulators of rumen methanogenesis. In this review, we explored biochemical pathways competing with methanogenesis that, potentially, could be modulated by the use of DFM. Pathways involving the redirection of H2 away from methanogenesis and pathways producing less H2 during feed fermentation are the preferred options. Propionate formation is an example of the latter option that in addition to decrease CH4 formation increases the retention of energy from the diet. Homoacetogenesis is a pathway using H2 to produce acetate, however up to now no acetogen has been shown to efficiently compete with methanogens in the rumen. Nitrate and sulphate reduction are pathways competing with methanogenesis, but the availability of these substances in the rumen is limited. Although there were studies using nitrate and sulphate as chemical additives, use of DFM for improving these processes and decrease the accumulation of toxic metabolites needs to be explored more. There are some other pathways such as methanotrophy and capnophily or modes of action such as inhibition of methanogens that theoretically could be provided by DFM and affect methanogenesis. We conclude that DFM is a promising alternative for rumen methane mitigation that should be further explored for their practical usage.

Did state renewable portfolio standards induce technical change in methane mitigation in the U.S. landfill sector?

NASA Astrophysics Data System (ADS)

Delhotal, Katherine Casey

Landfill gas (LFG) projects use the gas created from decomposing waste, which is approximately 49% methane, and substitute it for natural gas in engines, boilers, turbines, and other technologies to produce energy or heat. The projects are beneficial in terms of increased safety at the landfill, production of a cost-effective source of energy or heat, reduced odor, reduced air pollution emissions, and reduced greenhouse gas emissions. However, landfills sometimes face conflicting policy incentives. The theory of technical change shows that the diffusion of a technology or groups of technologies increases slowly in the beginning and then picks up speed as knowledge and better understanding of using the technology diffuses among potential users. Using duration analysis, data on energy prices, State and Federal policies related to landfill gas, renewable energy, and air pollution, as well as control data on landfill characteristics, I estimate the influence and direction of influence of renewable portfolio standards (RPS). The analysis found that RPS positively influences the diffusion of landfill gas technologies, encouraging landfills to consider electricity generation projects over direct sales of LFG to another facility. Energy price increases or increased revenues for a project are also critical. Barriers to diffusion include air emission permits in non-attainment areas and policies, such as net metering, which promote other renewables over LFG projects. Using the estimates from the diffusion equations, I analyze the potential influence of a Federal RPS as well as the potential interaction with a Federal, market based climate change policy, which will increase the revenue of a project through higher energy sale prices. My analysis shows that a market based climate change policy such as a cap-and-trade or carbon tax scheme would increase the number of landfill gas projects significantly more than a Federal RPS.

The interaction of climate change and methane hydrates

USGS Publications Warehouse

Ruppel, Carolyn D.; Kessler, John D.

2017-01-01

Gas hydrate, a frozen, naturally-occurring, and highly-concentrated form of methane, sequesters significant carbon in the global system and is stable only over a range of low-temperature and moderate-pressure conditions. Gas hydrate is widespread in the sediments of marine continental margins and permafrost areas, locations where ocean and atmospheric warming may perturb the hydrate stability field and lead to release of the sequestered methane into the overlying sediments and soils. Methane and methane-derived carbon that escape from sediments and soils and reach the atmosphere could exacerbate greenhouse warming. The synergy between warming climate and gas hydrate dissociation feeds a popular perception that global warming could drive catastrophic methane releases from the contemporary gas hydrate reservoir. Appropriate evaluation of the two sides of the climate-methane hydrate synergy requires assessing direct and indirect observational data related to gas hydrate dissociation phenomena and numerical models that track the interaction of gas hydrates/methane with the ocean and/or atmosphere. Methane hydrate is likely undergoing dissociation now on global upper continental slopes and on continental shelves that ring the Arctic Ocean. Many factors—the depth of the gas hydrates in sediments, strong sediment and water column sinks, and the inability of bubbles emitted at the seafloor to deliver methane to the sea-air interface in most cases—mitigate the impact of gas hydrate dissociation on atmospheric greenhouse gas concentrations though. There is no conclusive proof that hydrate-derived methane is reaching the atmosphere now, but more observational data and improved numerical models will better characterize the climate-hydrate synergy in the future.

The interaction of climate change and methane hydrates

NASA Astrophysics Data System (ADS)

Ruppel, Carolyn D.; Kessler, John D.

2017-03-01

Gas hydrate, a frozen, naturally-occurring, and highly-concentrated form of methane, sequesters significant carbon in the global system and is stable only over a range of low-temperature and moderate-pressure conditions. Gas hydrate is widespread in the sediments of marine continental margins and permafrost areas, locations where ocean and atmospheric warming may perturb the hydrate stability field and lead to release of the sequestered methane into the overlying sediments and soils. Methane and methane-derived carbon that escape from sediments and soils and reach the atmosphere could exacerbate greenhouse warming. The synergy between warming climate and gas hydrate dissociation feeds a popular perception that global warming could drive catastrophic methane releases from the contemporary gas hydrate reservoir. Appropriate evaluation of the two sides of the climate-methane hydrate synergy requires assessing direct and indirect observational data related to gas hydrate dissociation phenomena and numerical models that track the interaction of gas hydrates/methane with the ocean and/or atmosphere. Methane hydrate is likely undergoing dissociation now on global upper continental slopes and on continental shelves that ring the Arctic Ocean. Many factors—the depth of the gas hydrates in sediments, strong sediment and water column sinks, and the inability of bubbles emitted at the seafloor to deliver methane to the sea-air interface in most cases—mitigate the impact of gas hydrate dissociation on atmospheric greenhouse gas concentrations though. There is no conclusive proof that hydrate-derived methane is reaching the atmosphere now, but more observational data and improved numerical models will better characterize the climate-hydrate synergy in the future.

The interaction of climate change and methane hydrates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruppel, Carolyn D.; Kessler, John D.

Gas hydrate, a frozen, naturally-occurring, and highly-concentrated form of methane, sequesters significant carbon in the global system and is stable only over a range of low-temperature and moderate-pressure conditions. Gas hydrate is widespread in the sediments of marine continental margins and permafrost areas, locations where ocean and atmospheric warming may perturb the hydrate stability field and lead to release of the sequestered methane into the overlying sediments and soils. Methane and methane-derived carbon that escape from sediments and soils and reach the atmosphere could exacerbate greenhouse warming. The synergy between warming climate and gas hydrate dissociation feeds a popular perceptionmore » that global warming could drive catastrophic methane releases from the contemporary gas hydrate reservoir. Appropriate evaluation of the two sides of the climate-methane hydrate synergy requires assessing direct and indirect observational data related to gas hydrate dissociation phenomena and numerical models that track the interaction of gas hydrates/methane with the ocean and/or atmosphere. Methane hydrate is likely undergoing dissociation now on global upper continental slopes and on continental shelves that ring the Arctic Ocean. Many factors—the depth of the gas hydrates in sediments, strong sediment and water column sinks, and the inability of bubbles emitted at the seafloor to deliver methane to the sea-air interface in most cases—mitigate the impact of gas hydrate dissociation on atmospheric greenhouse gas concentrations though. There is no conclusive proof that hydrate-derived methane is reaching the atmosphere now, but more observational data and improved numerical models will better characterize the climate-hydrate synergy in the future.« less

The interaction of climate change and methane hydrates

DOE PAGES

Ruppel, Carolyn D.; Kessler, John D.

2016-12-14

Gas hydrate, a frozen, naturally-occurring, and highly-concentrated form of methane, sequesters significant carbon in the global system and is stable only over a range of low-temperature and moderate-pressure conditions. Gas hydrate is widespread in the sediments of marine continental margins and permafrost areas, locations where ocean and atmospheric warming may perturb the hydrate stability field and lead to release of the sequestered methane into the overlying sediments and soils. Methane and methane-derived carbon that escape from sediments and soils and reach the atmosphere could exacerbate greenhouse warming. The synergy between warming climate and gas hydrate dissociation feeds a popular perceptionmore » that global warming could drive catastrophic methane releases from the contemporary gas hydrate reservoir. Appropriate evaluation of the two sides of the climate-methane hydrate synergy requires assessing direct and indirect observational data related to gas hydrate dissociation phenomena and numerical models that track the interaction of gas hydrates/methane with the ocean and/or atmosphere. Methane hydrate is likely undergoing dissociation now on global upper continental slopes and on continental shelves that ring the Arctic Ocean. Many factors—the depth of the gas hydrates in sediments, strong sediment and water column sinks, and the inability of bubbles emitted at the seafloor to deliver methane to the sea-air interface in most cases—mitigate the impact of gas hydrate dissociation on atmospheric greenhouse gas concentrations though. There is no conclusive proof that hydrate-derived methane is reaching the atmosphere now, but more observational data and improved numerical models will better characterize the climate-hydrate synergy in the future.« less

Amplitude versus offset analysis to marine seismic data acquired in Nankai Trough, offshore Japan where methane hydrate exists

NASA Astrophysics Data System (ADS)

Hato, M.; Inamori, T.; Matsuoka, T.; Shimizu, S.

2003-04-01

Occurrence of methane hydrates in the Nankai Trough, located off the south-eastern coast of Japan, was confirmed by the exploratory test well drilling conducted by Japan’s Ministry of International Trade and Industry in 1999. Confirmation of methane hydrate has given so big impact to the Japan's future energy strategy and scientific and technological interest was derived from the information of the coring and logging results at the well. Following the above results, Japan National Oil Corporation (JNOC) launched the national project, named as MH21, for establishing the technology of methane hydrate exploration and related technologies such as production and development. As one of the research project for evaluating the total amount of the methane hydrate, Amplitude versus Offset (AVO) was applied to the seismic data acquired in the Nankai Trough area. The main purpose of the AVO application is to evaluate the validity of delineation of methane hydrate-bearing zones. Since methane hydrate is thought to accompany with free-gas in general just below the methane hydrate-bearing zones, the AVO has a possibility of describing the presence of free-gas. The free-gas is thought to be located just below the base of methane hydrate stability zone which is characterized by the Bottom Simulating Reflectors (BSRs) on the seismic section. In this sense, AVO technology, which was developed as gas delineation tools, can be utilized for methane hydrate exploration. The result of AVO analysis clearly shows gas-related anomaly below the BSRs. Appearance of the AVO anomaly has so wide variety. Some of the anomalies might not correspond to the free-gas existence, however, some of them may show free-gas. We are now going to develop methodology to clearly discriminate free-gas from non-gas zone by integrating various types of seismic methods such as seismic inversion and seismic attribute analysis.

Measuring Methane from Cars, Ships, Airplanes, Helicopters and Drones Using High-Speed Open-Path Technology

NASA Astrophysics Data System (ADS)

Burba, George; Anderson, Tyler; Biraud, Sebastien; Caulton, Dana; von Fischer, Joe; Gioli, Beniamino; Hanson, Chad; Ham, Jay; Kohnert, Katrin; Larmanou, Eric; Levy, Peter; Polidori, Andrea; Pikelnaya, Olga; Sachs, Torsten; Serafimovich, Andrei; Zaldei, Alessandro; Zondlo, Mark; Zulueta, Rommel

2017-04-01

Methane plays a critical role in the radiation balance, chemistry of the atmosphere, and air quality. The major anthropogenic sources of methane include oil and gas development sites, natural gas distribution networks, landfill emissions, and agricultural production. The majority of oil and gas and urban methane emission occurs via variable-rate point sources or diffused spots in topographically challenging terrains (e.g., street tunnels, elevated locations at water treatment plants, vents, etc.). Locating and measuring such methane emissions is challenging when using traditional micrometeorological techniques, and requires development of novel approaches. Landfill methane emissions traditionally assessed at monthly or longer time intervals are subject to large uncertainties because of the snapshot nature of the measurements and the barometric pumping phenomenon. The majority of agricultural and natural methane production occurs in areas with little infrastructure or easily available grid power (e.g., rice fields, arctic and boreal wetlands, tropical mangroves, etc.). A lightweight, high-speed, high-resolution, open-path technology was recently developed for eddy covariance measurements of methane flux, with power consumption 30-150 times below other available technologies. It was designed to run on solar panels or a small generator and be placed in the middle of the methane-producing ecosystem without a need for grid power. Lately, this instrumentation has been utilized increasingly more frequently outside of the traditional use on stationary flux towers. These novel approaches include measurements from various moving platforms, such as cars, aircraft, and ships. Projects included mapping of concentrations and vertical profiles, leak detection and quantification, mobile emission detection from natural gas-powered cars, soil methane flux surveys, etc. This presentation will describe the latest state of the key projects utilizing the novel lightweight low-power high-resolution open-path technology, and will highlight several novel approaches where such instrumentation was used in mobile deployments in urban, agricultural and natural environments by academic institutions, regulatory agencies and industry.

Quantification of methane fluxes from industrial sites using a combination of a tracer release method and a Gaussian model

NASA Astrophysics Data System (ADS)

Ars, S.; Broquet, G.; Yver-Kwok, C.; Wu, L.; Bousquet, P.; Roustan, Y.

2015-12-01

Greenhouse gas (GHG) concentrations keep on increasing in the atmosphere since industrial revolution. Methane (CH4) is the second most important anthropogenic GHG after carbon dioxide (CO2). Its sources and sinks are nowadays well identified however their relative contributions remain uncertain. The industries and the waste treatment emit an important part of the anthropogenic methane that is difficult to quantify because the sources are fugitive and discontinuous. A better estimation of methane emissions could help industries to adapt their mitigation's politic and encourage them to install methane recovery systems in order to reduce their emissions while saving money. Different methods exist to quantify methane emissions. Among them is the tracer release method consisting in releasing a tracer gas near the methane source at a well-known rate and measuring both their concentrations in the emission plume. The methane rate is calculated using the ratio of methane and tracer concentrations and the emission rate of the tracer. A good estimation of the methane emissions requires a good differentiation between the methane actually emitted by the site and the methane from the background concentration level, but also a good knowledge of the sources distribution over the site. For this purpose, a Gaussian plume model is used in addition to the tracer release method to assess the emission rates calculated. In a first step, the data obtained for the tracer during a field campaign are used to tune the model. Different model's parameterizations have been tested to find the best representation of the atmospheric dispersion conditions. Once these parameters are set, methane emissions are estimated thanks to the methane concentrations measured and a Bayesian inversion. This enables to adjust the position and the emission rate of the different methane sources of the site and remove the methane background concentration.

Nitrogen oxides and methane treatment by non-thermal plasma

NASA Astrophysics Data System (ADS)

Alva, E.; Pacheco, M.; Colín, A.; Sánchez, V.; Pacheco, J.; Valdivia, R.; Soria, G.

2015-03-01

Non thermal plasma was used to treat nitrogen oxides (NOx) and methane (CH4), since they are important constituents of hydrocarbon combustion emissions processes and, both gases, play a key role in the formation of tropospheric ozone. These gases are involved in environmental problems like acid rain and some diseases such as bronchitis and pneumonia. In the case of methane is widely known its importance in the global climate change, and currently accounts for 30% of global warming. There is a growing concern for methane leaks, associated with a rapid expansion of unconventional oil and gas extraction techniques as well as a large-scale methane release from Arctic because of ice melting and the subsequent methane production of decaying organic matter. Therefore, methane mitigation is a key to avoid dangerous levels of global warming. The research, here reported, deals about the generation of non-thermal plasma with a double dielectric barrier (2DBD) at atmospheric pressure with alternating current (AC) for NOx and CH4 treatment. The degradation efficiencies and their respective power consumption for different reactor configurations (cylindrical and planar) are also reported. Qualitative and quantitative analysis of gases degradation are reported before and after treatment with cold plasma. Experimental and theoretical results are compared obtaining good removal efficiencies, superior to 90% and to 20% respectively for NOx and CH4.

Valuing the ozone-related health benefits of methane emission controls

DOE PAGES

Sarofim, Marcus C.; Waldhoff, Stephanie T.; Anenberg, Susan C.

2015-06-29

Methane is a greenhouse gas that oxidizes to form ground-level ozone, itself a greenhouse gas and a health-harmful air pollutant. Reducing methane emissions will both slow anthropogenic climate change and reduce ozone-related mortality. We estimate the benefits of reducing methane emissions anywhere in the world for ozone-related premature mortality globally and for eight geographic regions. Our methods are consistent with those used by the US Government to estimate the social cost of carbon (SCC). We find that the global short- and long-term premature mortality benefits due to reduced ozone production from methane mitigation are (2011) $790 and $1775 per tonnemore » methane, respectively. These correspond to approximately 70 and 150 % of the valuation of methane’s global climate impacts using the SCC after extrapolating from carbon dioxide to methane using global warming potential estimates. Results for monetized benefits are sensitive to a number of factors, particularly the choice of elasticity to income growth used when calculating the value of a statistical life. The benefits increase for emission years further in the future. Regionally, most of the global mortality benefits accrue in Asia, but 10 % accrue in the United States. As a result, this methodology can be used to assess the benefits of methane emission reductions anywhere in the world, including those achieved by national and multinational policies.« less

Comparative use of different emission measurement approaches to determine methane emissions from a biogas plant.

PubMed

Reinelt, Torsten; Delre, Antonio; Westerkamp, Tanja; Holmgren, Magnus A; Liebetrau, Jan; Scheutz, Charlotte

2017-10-01

A sustainable anaerobic biowaste treatment has to mitigate methane emissions from the entire biogas production chain, but the exact quantification of these emissions remains a challenge. This study presents a comparative measurement campaign carried out with on-site and ground-based remote sensing measurement approaches conducted by six measuring teams at a Swedish biowaste treatment plant. The measured emissions showed high variations, amongst others caused by different periods of measurement performance in connection with varying operational states of the plant. The overall methane emissions measured by ground-based remote sensing varied from 5 to 25kgh -1 (corresponding to a methane loss of 0.6-3.0% of upgraded methane produced), depending on operating conditions and the measurement method applied. Overall methane emissions measured by the on-site measuring approaches varied between 5 and 17kgh -1 (corresponding to a methane loss of 0.6 and 2.1%) from team to team, depending on the number of measured emission points, operational state during the measurements and the measurement method applied. Taking the operational conditions into account, the deviation between different approaches and teams could be explained, in that the two largest methane-emitting sources, contributing about 90% of the entire site's emissions, were found to be the open digestate storage tank and a pressure release valve on the compressor station. Copyright © 2017. Published by Elsevier Ltd.

Sealing rice field boundaries in Bangladesh: a pilot study demonstrating reductions in water use, arsenic loading to field soils, and methane emissions from irrigation water.

PubMed

Neumann, Rebecca B; Pracht, Lara E; Polizzotto, Matthew L; Badruzzaman, A Borhan M; Ali, M Ashraf

2014-08-19

Irrigation of rice fields in Bangladesh with arsenic-contaminated and methane-rich groundwater loads arsenic into field soils and releases methane into the atmosphere. We tested the water-savings potential of sealing field bunds (raised boundaries around field edges) as a way to mitigate these negative outcomes. We found that, on average, bund sealing reduced seasonal water use by 52 ± 17% and decreased arsenic loading to field soils by 15 ± 4%; greater savings in both water use and arsenic loading were achieved in fields with larger perimeter-to-area ratios (i.e., smaller fields). Our study is the first to quantify emission of methane from irrigation water in Bangladesh, a currently unaccounted-for methane source. Irrigation water applied to unsealed fields at our site emits 18 to 31 g of methane per square-meter of field area per season, potentially doubling the atmospheric input of methane from rice cultivation. Bund sealing reduced the emission of methane from irrigation water by 4 to 19 g/m(2). While the studied outcomes of bund sealing are positive and compelling, widespread implementation of the technique should consider other factors, such as effect on yields, financial costs, and impact on the hydrologic system. We provide an initial and preliminary assessment of these implementation factors.

Valuing the ozone-related health benefits of methane emission controls

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sarofim, Marcus C.; Waldhoff, Stephanie T.; Anenberg, Susan C.

Methane is a greenhouse gas that oxidizes to form ground-level ozone, itself a greenhouse gas and a health-harmful air pollutant. Reducing methane emissions will both slow anthropogenic climate change and reduce ozone-related mortality. We estimate the benefits of reducing methane emissions anywhere in the world for ozone-related premature mortality globally and for eight geographic regions. Our methods are consistent with those used by the US Government to estimate the social cost of carbon (SCC). We find that the global short- and long-term premature mortality benefits due to reduced ozone production from methane mitigation are (2011) $790 and $1775 per tonnemore » methane, respectively. These correspond to approximately 70 and 150 % of the valuation of methane’s global climate impacts using the SCC after extrapolating from carbon dioxide to methane using global warming potential estimates. Results for monetized benefits are sensitive to a number of factors, particularly the choice of elasticity to income growth used when calculating the value of a statistical life. The benefits increase for emission years further in the future. Regionally, most of the global mortality benefits accrue in Asia, but 10 % accrue in the United States. As a result, this methodology can be used to assess the benefits of methane emission reductions anywhere in the world, including those achieved by national and multinational policies.« less

Two-stream Convolutional Neural Network for Methane Emissions Quantification

NASA Astrophysics Data System (ADS)

Wang, J.; Ravikumar, A. P.; McGuire, M.; Bell, C.; Tchapmi, L. P.; Brandt, A. R.

2017-12-01

Methane, a key component of natural gas, has a 25x higher global warming potential than carbon dioxide on a 100-year basis. Accurately monitoring and mitigating methane emissions require cost-effective detection and quantification technologies. Optical gas imaging, one of the most commonly used leak detection technology, adopted by Environmental Protection Agency, cannot estimate leak-sizes. In this work, we harness advances in computer science to allow for rapid and automatic leak quantification. Particularly, we utilize two-stream deep Convolutional Networks (ConvNets) to estimate leak-size by capturing complementary spatial information from still plume frames, and temporal information from plume motion between frames. We build large leak datasets for training and evaluating purposes by collecting about 20 videos (i.e. 397,400 frames) of leaks. The videos were recorded at six distances from the source, covering 10 -60 ft. Leak sources included natural gas well-heads, separators, and tanks. All frames were labeled with a true leak size, which has eight levels ranging from 0 to 140 MCFH. Preliminary analysis shows that two-stream ConvNets provides significant accuracy advantage over single steam ConvNets. Spatial stream ConvNet can achieve an accuracy of 65.2%, by extracting important features, including texture, plume area, and pattern. Temporal stream, fed by the results of optical flow analysis, results in an accuracy of 58.3%. The integration of the two-stream ConvNets gives a combined accuracy of 77.6%. For future work, we will split the training and testing datasets in distinct ways in order to test the generalization of the algorithm for different leak sources. Several analytic metrics, including confusion matrix and visualization of key features, will be used to understand accuracy rates and occurrences of false positives. The quantification algorithm can help to find and fix super-emitters, and improve the cost-effectiveness of leak detection and repair programs.

Methane - fuel for the future

DOE Office of Scientific and Technical Information (OSTI.GOV)

McGeer, P.; Durbin, E.

1982-01-01

The 20 invited papers presented at the world conference on alternative fuel entitled 'Methane - fuel for the future' form the basis of this book. Papers discuss: the availability of alternative fuels (natural gas, biomass conversion to methane, methane from coal conversion); technological adaptions for alternative fuels (e.g. natural gas fueled engines, methane and diesel engines); commercial experience with alternative fuel programs. (e.g. retailing of methane); and some national programs for alternative fuels. One paper has been abstracted separately.

Methane emissions in the Marcellus, top down constraints on emission growth with increasing production

NASA Astrophysics Data System (ADS)

DeCarlo, P. F.; Goetz, J. D.

2017-12-01

Emission inventories in the state of Pennsylvania are largely self-reported numbers by industry and significantly underestimate methane emissions at the facility level compared to measured emissions. Nevertheless, these emission inventories are used in making policy decisions at the state level with regard to reduction and mitigation of methane emissions from oil and gas development. A series of measurements made in northeastern Pennsylvania in 2012 and 2015 provide data for comparison to reported emission inventories at the facility level and changes in total emissions at the state and regional level. Tracer release studies performed in 2012 indicate up to an order of magnitude underestimate for facility level emissions. A novel methane background analysis on the 2012 and 2015 datasets indicates approximately a 300% increase in methane emissions over that three-year period scaling with increasing natural gas in the northeast region of Pennsylvania. State emission inventories indicate an 11% decrease over the same time period clearly at odds with the measurements. This presentation will also discuss potential areas of discrepancy with the emission inventories.

Effects of granular activated carbon on methane removal performance and methanotrophic community of a lab-scale bioreactor.

PubMed

Lee, Eun-Hee; Choi, Sun-Ah; Yi, Taewoo; Kim, Tae Gwan; Lee, Sang-Don; Cho, Kyung-Suk

2015-01-01

Two identical lab-scale bioreactor systems were operated to examine the effects of granular activated carbon (GAC) on methane removal performance and methanotrophic community. Both bioreactor systems removed methane completely at a CH4 loading rate of 71.2 g-CH4·d(-1) for 17 days. However, the methane removal efficiency declined to 88% in the bioreactor without GAC, while the bioreactor amended with GAC showed greater methane removal efficiency of 97% at a CH4 loading rate of 107.5 g-CH4·d(-1). Although quantitative real-time PCR showed that methanotrophic populations were similar levels of 5-10 × 10(8) pmoA gene copy number·VSS(-1) in both systems, GAC addition changed the methanotrophic community composition of the bioreactor systems. Microarray assay revealed that GAC enhanced the type I methanotrophic genera including Methylobacter, Methylomicrobium, and Methylomonas of the system, which suggests that GAC probably provided a favorable environment for type I methanotrophs. These results indicated that GAC is a promising support material in bioreactor systems for CH4 mitigation.

Co-development of climate smart flooded rice farming systems

NASA Astrophysics Data System (ADS)

de Neergaard, Andreas; Stoumann Jensen, Lars; Ly, Proyuth; Pandey, Arjun; Duong Vu, Quynh; Tariq, Azeem; Islam, Syed; van Groenigen, Jan Willem; Sander, Bjoern Ole; de Tourdonnet, Stephane; Van Mai, Trinh; Wassmann, Reiner

2017-04-01

Mid-season drainage in flooded rice is known to reduce CH4 emission, while effects on N2O emission are more variable. Banning of crop-residue burning, and growing markets for organically fertilized rice, are resulting in systems with larger reactive C input, and potentially larger methane emissions. Tight farming systems with 2 or 3 annual crops are effective in mitigating emissions, in that the land sparing value is high, but put serious constraints on mitigation options under increased C input scenarios. In a series of field (Cambodia, Philippines and Vietnam) and greenhouse experiments, we investigated the effect of a variety of organic amendments and wetting and drying cycles on yield and GHG emissions. Specifically we have tested the effect of inserting very early, or even-pre-planting drainage, as a means to accelerate turnover of straw or other C sources, and reduce methane emission later in the season. Overall, our results showed that drying periods had minimal impact on yields, while reducing overall GHG emission. Methane emission was strongly controlled by C availability in the substrate (on equal total C-input basis), increasing in the order: biochar-composts-animal manure-fresh material. Nitrous oxide emissions generally increased with draining cycles, but did not lead to overall increase in GHG emissions as its contribution was balanced by lowered CH4 emissions. Growth chamber experiments showed that methane emission was significantly reduced for extended periods after re-flooding, hence the idea of early drainage was developed. Meanwhile, Cambodian farmers expressed concerns over re-supply of water after drainage. In response to that, we tested if early-season drainage could replace mid-season drainage. With addition of labile carbon substrates (straw) duration of early season drainage was more important for reducing GHG emissions, than duration of mid-season drainage, and had the highest potential for total emission reduction. In a farmers-field trial in Vietnam, pre-planting and early season drainage was tested in spring and summer rice, under individual and community water management regimes, and at 2 straw application levels. Pre-season drainage was difficult for farmers to implement, due to the short duration of fallow between cropping seasons. Early season drainage was most effective in lowering methane emissions at both straw application levels. Unsurprisingly, the well-managed drainage control (community system) was significantly more effective in mitigating emissions, than the individually water management. Surveys among farming communities in Philippines, subject to agricultural campaigns on alternate-wetting-and-drying showed higher adoption among farmers who actively pumped water to their fields, compared to gravity-fed water supply, due to the direct savings experienced by farmers pumping water. Several other factors positively influenced adoption of mitigation techniques, including education level, access to extension services, wealth and farm size, and age of farmer (negatively correlated to adoption rate). In conclusion, drainage periods are even more important to mitigate emissions when including organic manures or residues in flooded rice, and early-season drainage should be further explored as a more safe and convenient option for smallholders. Participatory development of climate smart prototypes will be essential, and a model for such is presented.

Greenhouse gases: low methane leakage from gas pipelines.

PubMed

Lelieveld, J; Lechtenböhmer, S; Assonov, S S; Brenninkmeijer, C A M; Dienst, C; Fischedick, M; Hanke, T

2005-04-14

Using natural gas for fuel releases less carbon dioxide per unit of energy produced than burning oil or coal, but its production and transport are accompanied by emissions of methane, which is a much more potent greenhouse gas than carbon dioxide in the short term. This calls into question whether climate forcing could be reduced by switching from coal and oil to natural gas. We have made measurements in Russia along the world's largest gas-transport system and find that methane leakage is in the region of 1.4%, which is considerably less than expected and comparable to that from systems in the United States. Our calculations indicate that using natural gas in preference to other fossil fuels could be useful in the short term for mitigating climate change.

Comparison of physically- and economically-based CO2-equivalences for methane

NASA Astrophysics Data System (ADS)

Boucher, O.

2012-05-01

There is a controversy on the role methane (and other short-lived species) should play in climate mitigation policies, and there is no consensus on what an optimal methane CO2-equivalence should be. We revisit this question by discussing some aspects of physically-based (i.e. global- warming potential or GWP and global temperature change potential or GTP) and socio-economically-based climate metrics. To this effect we use a simplified global damage potential (GDP) that was introduced by earlier authors and investigate the uncertainties in the methane CO2-equivalence that arise from physical and socio-economic factors. The median value of the methane GDP comes out very close to the widely used methane 100-yr GWP because of various compensating effects. However, there is a large spread in possible methane CO2-equivalences from this metric (1-99% interval: 10.0-42.5; 5-95% interval: 12.5-38.0) that is essentially due to the choice in some socio-economic parameters (i.e. the damage cost function and the discount rate). The main factor differentiating the methane 100-yr GTP from the methane 100-yr GWP and the GDP is the fact that the former metric is an end-point metric, whereas the latter are cumulative metrics. There is some rationale for an increase in the methane CO2-equivalence in the future as global warming unfolds, as implied by a convex damage function in the case of the GDP metric. We also show that a methane CO2-equivalence based on a pulse emission is sufficient to inform multi-year climate policies and emissions reductions, as long as there is enough visibility on CO2 prices and CO2-equivalences for the stakeholders.

A strategic approach to selecting policy mechanisms for addressing coal mine methane emissions: A case study on Kazakhstan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roshchanka, Volha; Evans, Meredydd; Ruiz, Felicia

Coal production globally is projected to grow in the foreseeable future. Countries with heavy reliance on coal could reduce methane and other emissions through the capture and utilization of coal mine methane (CMM) in the short and medium term, while they pursue structural and long-term economic changes. Several countries have successfully implemented policies to promote CMM capture and utilization; however, some countries still struggle to implement projects. This paper outlines key factors to consider in adapting policies for CMM mitigation. The authors propose an approach for selecting adequate mechanisms for stimulating CMM mitigation that involves reviewing global best practices andmore » categorizing them functionally either as mechanisms needed to improve the underlying conditions or as CMM-specific policies. It is important to understand local policy frameworks and to consider whether it is more feasible to improve underlying policy conditions or to provide targeted incentives as an interim measure. Using Kazakhstan as a case study, the authors demonstrate how policymakers could assess the overall policy framework to find the most promising options to facilitate CMM projects. Kazakhstan’s emissions from underground coal mines have been increasing both in total and per tonne of coal production, while overall production has been declining. CMM mitigation presents an opportunity for the country to reduce its greenhouse gas emissions in the near and medium term, while the government pursues sustainable development goals. Analysis shows that policymakers in Kazakhstan can leverage existing policies to stimulate utilization by extending feed-in tariffs to cover CMM and by developing working methodologies for companies to obtain emission reduction credits from CMM projects.« less

Green-house gas mitigation capacity of a small scale rural biogas plant calculations for Bangladesh through a general life cycle assessment.

PubMed

Rahman, Khondokar M; Melville, Lynsey; Fulford, David; Huq, Sm Imamul

2017-10-01

Calculations towards determining the greenhouse gas mitigation capacity of a small-scale biogas plant (3.2 m 3 plant) using cow dung in Bangladesh are presented. A general life cycle assessment was used, evaluating key parameters (biogas, methane, construction materials and feedstock demands) to determine the net environmental impact. The global warming potential saving through the use of biogas as a cooking fuel is reduced from 0.40 kg CO 2 equivalent to 0.064 kg CO 2 equivalent per kilogram of dung. Biomethane used for cooking can contribute towards mitigation of global warming. Prior to utilisation of the global warming potential of methane (from 3.2 m 3 biogas plant), the global warming potential is 13 t of carbon dioxide equivalent. This reduced to 2 t as a result of complete combustion of methane. The global warming potential saving of a bioenergy plant across a 20-year life cycle is 217 t of carbon dioxide equivalent, which is 11 t per year. The global warming potential of the resultant digestate is zero and from construction materials is less than 1% of total global warming potential. When the biogas is used as a fuel for cooking, the global warming potential will reduce by 83% compare with the traditional wood biomass cooking system. The total 80 MJ of energy that can be produced from a 3.2 m 3 anaerobic digestion plant would replace 1.9 t of fuel wood or 632 kg of kerosene currently used annually in Bangladesh. The digestate can also be used as a nutrient rich fertiliser substituting more costly inorganic fertilisers, with no global warming potential impact.

Fermentation Enhancement of Methanogenic Archaea Consortia from an Illinois Basin Coalbed via DOL Emulsion Nutrition

PubMed Central

Xiao, Dong; Peng, Su-Ping; Wang, En-Yuan

2015-01-01

Microbially enhanced coalbed methane technology must be used to increase the methane content in mining and generate secondary biogenic gas. In this technology, the metabolic processes of methanogenic consortia are the basis for the production of biomethane from some of the organic compounds in coal. Thus, culture nutrition plays an important role in remediating the nutritional deficiency of a coal seam. To enhance the methane production rates for microorganism consortia, different types of nutrition solutions were examined in this study. Emulsion nutrition solutions containing a novel nutritional supplement, called dystrophy optional modification latex, increased the methane yield for methanogenic consortia. This new nutritional supplement can help methanogenic consortia form an enhanced anaerobic environment, optimize the microbial balance in the consortia, and improve the methane biosynthesis rate. PMID:25884952

Mitigating global warming potentials of methane and nitrous oxide gases from rice paddies under different irrigation regimes.

PubMed

Ali, Muhammad Aslam; Hoque, M Anamul; Kim, Pil Joo

2013-04-01

A field experiment was conducted in Bangladesh Agricultural University Farm to investigate the mitigating effects of soil amendments such as calcium carbide, calcium silicate, phosphogypsum, and biochar with urea fertilizer on global warming potentials (GWPs) of methane (CH4) and nitrous oxide (N2O) gases during rice cultivation under continuous and intermittent irrigations. Among the amendments phosphogypsum and silicate fertilizer, being potential source of electron acceptors, decreased maximum level of seasonal CH4 flux by 25-27 % and 32-38 % in continuous and intermittent irrigations, respectively. Biochar and calcium carbide amendments, acting as nitrification inhibitors, decreased N2O emissions by 36-40 % and 26-30 % under continuous and intermittent irrigations, respectively. The total GWP of CH4 and N2O gases were decreased by 7-27 % and 6-34 % with calcium carbide, phosphogypsum, and silicate fertilizer amendments under continuous and intermittent irrigations, respectively. However, biochar amendments increased overall GWP of CH4 and N2O gases.

Biocatalytic conversion of methane to methanol as a key step for development of methane-based biorefineries.

PubMed

Hwang, In Yeub; Lee, Seung Hwan; Choi, Yoo Seong; Park, Si Jae; Na, Jeong Geol; Chang, In Seop; Kim, Choongik; Kim, Hyun Cheol; Kim, Yong Hwan; Lee, Jin Won; Lee, Eun Yeol

2014-12-28

Methane is considered as a next-generation carbon feedstock owing to the vast reserves of natural and shale gas. Methane can be converted to methanol by various methods, which in turn can be used as a starting chemical for the production of value-added chemicals using existing chemical conversion processes. Methane monooxygenase is the key enzyme that catalyzes the addition of oxygen to methane. Methanotrophic bacteria can transform methane to methanol by inhibiting methanol dehydrogenase. In this paper, we review the recent progress made on the biocatalytic conversion of methane to methanol as a key step for methane-based refinery systems and discuss future prospects for this technology.

Influence of Different Plant Species on Methane Emissions from Soil in a Restored Swiss Wetland

PubMed Central

Bhullar, Gurbir S.; Edwards, Peter J.; Olde Venterink, Harry

2014-01-01

Plants are a major factor influencing methane emissions from wetlands, along with environmental parameters such as water table, temperature, pH, nutrients and soil carbon substrate. We conducted a field experiment to study how different plant species influence methane emissions from a wetland in Switzerland. The top 0.5 m of soil at this site had been removed five years earlier, leaving a substrate with very low methanogenic activity. We found a sixfold difference among plant species in their effect on methane emission rates: Molinia caerulea and Lysimachia vulgaris caused low emission rates, whereas Senecio paludosus, Carex flava, Juncus effusus and Typha latifolia caused relatively high rates. Centaurea jacea, Iris sibirica, and Carex davalliana caused intermediate rates. However, we found no effect of either plant biomass or plant functional groups – based on life form or productivity of the habitat – upon methane emission. Emissions were much lower than those usually reported in temperate wetlands, which we attribute to reduced concentrations of labile carbon following topsoil removal. Thus, unlike most wetland sites, methane production in this site was probably fuelled chiefly by root exudation from living plants and from root decay. We conclude that in most wetlands, where concentrations of labile carbon are much higher, these sources account for only a small proportion of the methane emitted. Our study confirms that plant species composition does influence methane emission from wetlands, and should be considered when developing measures to mitigate the greenhouse gas emissions. PMID:24586894

Inverse Modelling of Global Methane Emissions: Past Achievement and Future Prospects of using Satellites

NASA Astrophysics Data System (ADS)

Houweling, S.; Pandey, S.; Segers, A.

2017-12-01

Methane is regarded as a suitable target for short-term climate mitigation, because of its relatively short atmospheric residence time compared to carbon dioxide and other long-lived greenhouse gases. However, to build climate policy on methane is complicated because of the uncertainties in its emission budget, reflected in the difficulty to predict its global growth rate. Several different and conflicting scenarios have been proposed in high profile journals to explain its recent evolution in the atmosphere. Since the early 2000s atmospheric methane is being measured by Earth orbiting satellites. Missions such as SCIAMACHY and GOSAT have largely increased the number of atmospheric methane measurements that are available for the quantification its emissions using inverse modelling techniques. In this presentation, we address the question what has been the role of satellite data in the discussion about the causes of the varying growth rate of methane, and what are the remaining limitations. This is the time when space borne remote sensing of methane is transitioning from exploratory scientific missions to monitoring missions, starting with the preoperational mission S5p TROPOMI to be launched in September 2017. In the meantime, also inverse modelling techniques are prepared for operational use in support of COP21 agreement to reduce greenhouse gas emissions. These developments bring new opportunities and challenges, which will be discussed.

Identification and characterization of high methane-emitting abandoned oil and gas wells

PubMed Central

Kang, Mary; Christian, Shanna; Celia, Michael A.; Mauzerall, Denise L.; Bill, Markus; Miller, Alana R.; Chen, Yuheng; Conrad, Mark E.; Darrah, Thomas H.; Jackson, Robert B.

2016-01-01

Recent measurements of methane emissions from abandoned oil/gas wells show that these wells can be a substantial source of methane to the atmosphere, particularly from a small proportion of high-emitting wells. However, identifying high emitters remains a challenge. We couple 163 well measurements of methane flow rates; ethane, propane, and n-butane concentrations; isotopes of methane; and noble gas concentrations from 88 wells in Pennsylvania with synthesized data from historical documents, field investigations, and state databases. Using our databases, we (i) improve estimates of the number of abandoned wells in Pennsylvania; (ii) characterize key attributes that accompany high emitters, including depth, type, plugging status, and coal area designation; and (iii) estimate attribute-specific and overall methane emissions from abandoned wells. High emitters are best predicted as unplugged gas wells and plugged/vented gas wells in coal areas and appear to be unrelated to the presence of underground natural gas storage areas or unconventional oil/gas production. Repeat measurements over 2 years show that flow rates of high emitters are sustained through time. Our attribute-based methane emission data and our comprehensive estimate of 470,000–750,000 abandoned wells in Pennsylvania result in estimated state-wide emissions of 0.04–0.07 Mt (1012 g) CH4 per year. This estimate represents 5–8% of annual anthropogenic methane emissions in Pennsylvania. Our methodology combining new field measurements with data mining of previously unavailable well attributes and numbers of wells can be used to improve methane emission estimates and prioritize cost-effective mitigation strategies for Pennsylvania and beyond. PMID:27849603

Overview of California's Efforts to Understand and Reduce Methane Sources

NASA Astrophysics Data System (ADS)

Croes, B. E.; Chen, Y.; Duren, R. M.; Falk, M.; Franco, G.; Herner, J.; Ingram, W.; Kuwayama, T.; McCarthy, R.; Scheehle, E.; Vijayan, A.

2016-12-01

Methane is an important short-lived climate pollutant (SLCP) and also has significant health implications as a tropospheric ozone precursor. As part of a comprehensive effort to reduce greenhouse gas (GHG) emissions overall by 40% from 1990 levels by 2030, California has proposed an SLCP Strategy that includes a 40% reduction of methane emissions from 2013 levels by 2030, with goals to reduce oil and gas related emissions and capture methane emissions from dairy operations and organic waste. A recent analysis of satellite data found a large methane "hot spot" over the Central Valley in California, likely the second largest over the entire U.S. In light of this finding, the California legislature passed Assembly Bill 1496 in 2015, which requires the California Air Resources Board (CARB) to undertake measurements to understand the sources of methane hot spots, evaluate life-cycle emissions from natural gas imported into California, and update relevant policies and programs. There is growing evidence in the recent scientific literature suggesting that a small fraction of methane sources within a category emit disproportionately higher emissions than their counterparts, usually referred to as "super emitters". As such, controlling these sources may provide a lower cost opportunity for methane reductions needed to meet near- and long-term climate goals. In order to achieve a comprehensive understanding of sources contributing to "hot spots", CARB, the California Energy Commission, and NASA's Jet Propulsion Laboratory are implementing a large-scale statewide methane survey using a tiered monitoring and measurement program, which will include airborne and ground-level measurements of the various regions and source sectors in the State. This presentation will discuss research and program implementation efforts to evaluate and mitigate methane super emitters and hot spots. These efforts are expected to improve our understanding of methane emission source distributions, improve the estimate of the overall magnitude of anthropogenic methane emissions in California, and inform and improve the effectiveness of methane reduction policies and programs.

Living Trees are a Major Source of Methane in the Temperate Forest

NASA Astrophysics Data System (ADS)

Covey, Kristofer

2017-04-01

Globally, forests sequester about 1.1 ± 0.8 Pg C yr-1, an ecosystem service worth hundreds of billions of dollars annually. Following the COP21 meeting in Paris, an international consensus emerged: The protection and expansion of forests worldwide is a necessary component of climate mitigation strategies to limit warming to less than 2°C. The physiological processes governing sequestration of CO2 in living trees are well studied and the resulting pattern in global forest carbon sequestration is clear. The role living trees play in the production and emission of methane (CH4) remains unclear, despite the fact it has the potential to offset climate benefits of forest CO2 sequestration. A known but largely unexplored pathway of forest CH4 production involves microbial-based methanogenesis in the wood of living trees. In the first regional-scale study of tree trunk gas composition, we examine the ubiquity and potential source strength of this pathway. Trunk methane concentrations were as high as 67.4% by volume (375,000-times atmospheric), with the highest concentrations found in older angiosperms (18,293 μLṡL-1 ± 3,096). Bark flux chambers from 23 living trees show emissions under field conditions, and large static chambers demonstrate high rates of production in felled Acer rubrum trunk sections. Diffusion flux modeling of trunk concentrations suggests wood-based microflora could produce a global CH4 efflux of 26 Tg CH4 yr-1. Applying these fluxes to provide a spatially explicit map of trunk-based CH4 flux, we estimate the potential relationship between carbon sequestration rates and CH4 emission by forest trees in Eastern North America. Methane emissions from the trunk-based methanogenic pathway could reduce the average climate mitigation value of these temperate forests by 10-30%. We highlight the need to improve earth systems models to account for the full complexity of forest climate interactions and provide a data layer useful in reducing large uncertainty in global methane budgets.

Climate Clever Clovers: New Paradigm to Reduce the Environmental Footprint of Ruminants by Breeding Low Methanogenic Forages Utilizing Haplotype Variation

PubMed Central

Kaur, Parwinder; Appels, Rudi; Bayer, Philipp E.; Keeble-Gagnere, Gabriel; Wang, Jiankang; Hirakawa, Hideki; Shirasawa, Kenta; Vercoe, Philip; Stefanova, Katia; Durmic, Zoey; Nichols, Phillip; Revell, Clinton; Isobe, Sachiko N.; Edwards, David; Erskine, William

2017-01-01

Mitigating methane production by ruminants is a significant challenge to global livestock production. This research offers a new paradigm to reduce methane emissions from ruminants by breeding climate-clever clovers. We demonstrate wide genetic diversity for the trait methanogenic potential in Australia’s key pasture legume, subterranean clover (Trifolium subterraneum L.). In a bi-parental population the broadsense heritability in methanogenic potential was moderate (H2 = 0.4) and allelic variation in a region of Chr 8 accounted for 7.8% of phenotypic variation. In a genome-wide association study we identified four loci controlling methanogenic potential assessed by an in vitro fermentation system. Significantly, the discovery of a single nucleotide polymorphism (SNP) on Chr 5 in a defined haplotype block with an upstream putative candidate gene from a plant peroxidase-like superfamily (TSub_g18548) and a downstream lectin receptor protein kinase (TSub_g18549) provides valuable candidates for an assay for this complex trait. In this way haplotype variation can be tracked to breed pastures with reduced methanogenic potential. Of the quantitative trait loci candidates, the DNA-damage-repair/toleration DRT100-like protein (TSub_g26967), linked to avoid the severity of DNA damage induced by secondary metabolites, is considered central to enteric methane production, as are disease resistance (TSub_g26971, TSub_g26972, and TSub_g18549) and ribonuclease proteins (TSub_g26974, TSub_g26975). These proteins are good pointers to elucidate the genetic basis of in vitro microbial fermentability and enteric methanogenic potential in subterranean clover. The genes identified allow the design of a suite of markers for marker-assisted selection to reduce rumen methane emission in selected pasture legumes. We demonstrate the feasibility of a plant breeding approach without compromising animal productivity to mitigate enteric methane emissions, which is one of the most significant challenges to global livestock production. PMID:28928752

The Potential Role of Seaweeds in the Natural Manipulation of Rumen Fermentation and Methane Production.

PubMed

Maia, Margarida R G; Fonseca, António J M; Oliveira, Hugo M; Mendonça, Carla; Cabrita, Ana R J

2016-08-30

This study is the first to evaluate the effects of five seaweeds (Ulva sp., Laminaria ochroleuca, Saccharina latissima, Gigartina sp., and Gracilaria vermiculophylla) on gas and methane production and ruminal fermentation parameters when incubated in vitro with two substrates (meadow hay and corn silage) for 24 h. Seaweeds led to lower gas production, with Gigartina sp. presenting the lowest value. When incubated with meadow hay, Ulva sp., Gigartina sp. and G. vermiculophylla decreased methane production, but with corn silage, methane production was only decreased by G. vermiculophylla. With meadow hay, L. ochroleuca and S. latissima promoted similar methane production as the control, but with corn silage, L. ochroleuca increased it. With the exception of S. latissima, all seaweeds promoted similar levels of total volatile fatty acid production. The highest proportion of acetic acid was produced with Ulva sp., G. vermiculophylla, and S. latissima; the highest proportion of butyric acid with the control and L. ochroleuca; and the highest proportion of iso-valeric acid with Gigartina sp. These results reveal the potential of seaweeds to mitigate ruminal methane production and the importance of the basal diet. To efficiently use seaweeds as feed ingredients with nutritional and environmental benefits, more research is required to determine the mechanisms underlying seaweed and substrate interactions.

The Potential Role of Seaweeds in the Natural Manipulation of Rumen Fermentation and Methane Production

PubMed Central

Maia, Margarida R. G.; Fonseca, António J. M.; Oliveira, Hugo M.; Mendonça, Carla; Cabrita, Ana R. J.

2016-01-01

This study is the first to evaluate the effects of five seaweeds (Ulva sp., Laminaria ochroleuca, Saccharina latissima, Gigartina sp., and Gracilaria vermiculophylla) on gas and methane production and ruminal fermentation parameters when incubated in vitro with two substrates (meadow hay and corn silage) for 24 h. Seaweeds led to lower gas production, with Gigartina sp. presenting the lowest value. When incubated with meadow hay, Ulva sp., Gigartina sp. and G. vermiculophylla decreased methane production, but with corn silage, methane production was only decreased by G. vermiculophylla. With meadow hay, L. ochroleuca and S. latissima promoted similar methane production as the control, but with corn silage, L. ochroleuca increased it. With the exception of S. latissima, all seaweeds promoted similar levels of total volatile fatty acid production. The highest proportion of acetic acid was produced with Ulva sp., G. vermiculophylla, and S. latissima; the highest proportion of butyric acid with the control and L. ochroleuca; and the highest proportion of iso-valeric acid with Gigartina sp. These results reveal the potential of seaweeds to mitigate ruminal methane production and the importance of the basal diet. To efficiently use seaweeds as feed ingredients with nutritional and environmental benefits, more research is required to determine the mechanisms underlying seaweed and substrate interactions. PMID:27572486

The Potential Role of Seaweeds in the Natural Manipulation of Rumen Fermentation and Methane Production

NASA Astrophysics Data System (ADS)

Maia, Margarida R. G.; Fonseca, António J. M.; Oliveira, Hugo M.; Mendonça, Carla; Cabrita, Ana R. J.

2016-08-01

This study is the first to evaluate the effects of five seaweeds (Ulva sp., Laminaria ochroleuca, Saccharina latissima, Gigartina sp., and Gracilaria vermiculophylla) on gas and methane production and ruminal fermentation parameters when incubated in vitro with two substrates (meadow hay and corn silage) for 24 h. Seaweeds led to lower gas production, with Gigartina sp. presenting the lowest value. When incubated with meadow hay, Ulva sp., Gigartina sp. and G. vermiculophylla decreased methane production, but with corn silage, methane production was only decreased by G. vermiculophylla. With meadow hay, L. ochroleuca and S. latissima promoted similar methane production as the control, but with corn silage, L. ochroleuca increased it. With the exception of S. latissima, all seaweeds promoted similar levels of total volatile fatty acid production. The highest proportion of acetic acid was produced with Ulva sp., G. vermiculophylla, and S. latissima; the highest proportion of butyric acid with the control and L. ochroleuca; and the highest proportion of iso-valeric acid with Gigartina sp. These results reveal the potential of seaweeds to mitigate ruminal methane production and the importance of the basal diet. To efficiently use seaweeds as feed ingredients with nutritional and environmental benefits, more research is required to determine the mechanisms underlying seaweed and substrate interactions.

Methane, Ethane, and Propane Sensor for Real-time Leak Detection and Diagnostics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roscioli, Joseph R.; Herndon, Scott; Nelson, David D.

2017-03-24

The Phase I effort demonstrated the technical viability of a fast, sensitive, mobile hydrocarbon monitor. The instrument will enable the oil and gas industry, researchers, and regulators to rapidly identify and chemically profile leaks from facilities. This capability will allow operators to quickly narrow down and mitigate probable leaking equipment, minimizing product loss and penalties due to regulatory non-compliance. During the initial development phase, we demonstrated operation of a prototype monitor that is capable of measuring methane, ethane, and propane at sub-part-per-billion sensitivities in 1 second, using direct absorption infrared spectroscopy. To our knowledge, this is the first instrument capablemore » of fast propane measurements at atmospheric concentrations. In addition, the electrical requirements of the monitor have been reduced from the 1,200 W typical of a spectrometer, to <500 W, making it capable of being powered by a passenger vehicle, and easily deployed by the industry. The prototype monitor leverages recent advances in laser technology, using high-efficiency interband cascade lasers to access the 3 μm region of the mid-infrared, where the methane, ethane, and propane absorptions are strongest. Combined with established spectrometer technology, we have achieved precisions below 200 ppt for each compound. This allows the monitor to measure fast plumes from oil and gas facilities, as well as ambient background concentrations (typical ambient levels are 2 ppm, 1.5 ppb, and 0.7 ppb for methane, ethane and propane, respectively). Increases in instrument operating pressure were studied in order to allow for a smaller 125 W pump to be used, and passive cooling was explored to reduce the cooling load by almost 90% relative to active (refrigerated) cooling. In addition, the simulated infrared absorption profiles of ethane and propane were modified to minimize crosstalk between species, achieving <1% crosstalk between ethane and propane. Finally, a monitor was designed based upon the commercial compact mini-spectrometer capable of dual-laser operation. We intend to build and test this during phase II. Multiple opportunities for improvement were also identified. First, the reported ethane and propane concentrations are susceptible to external acceleration acting upon the instrument. During phase II we will address this “motion-sickness”. Second, significant software development will be needed operate the monitor at 1 second resolution in real time, and provide rapid, actionable data to a driver or passenger.« less

Methyl-coenzyme M reductase A as an indicator to estimate methane production from dairy cows.

PubMed

Aguinaga Casañas, M A; Rangkasenee, N; Krattenmacher, N; Thaller, G; Metges, C C; Kuhla, B

2015-06-01

The evaluation of greenhouse gas mitigation strategies requires the quantitative assessment of individual methane production. Because methane measurement in respiration chambers is highly accurate, but also comprises various disadvantages such as limited capacity and high costs, the establishment of an indicator for estimating methane production of individual ruminants would provide an alternative to direct methane measurement. Methyl-coenzyme M reductase is involved in methanogenesis and the subunit α of methyl-coenzyme M reductase is encoded by the mcrA gene of rumen archaea. We therefore examined the relationship between methane emissions of Holstein dairy cows measured in respiration chambers with 2 different diets (high- and medium-concentrate diet) and the mcrA DNA and mcrA cDNA abundance determined from corresponding rumen fluid samples. Whole-body methane production per kilogram of dry matter intake and mcrA DNA normalized to the abundance of the rrs gene coding for 16S rRNA correlated significantly when using qmcrA primers. Use of qmcrA primers also revealed linear correlation between mcrA DNA copy number and methane yield. Regression analyses based on normalized mcrA cDNA abundances revealed no significant linear correlation with methane production per kilogram of dry matter intake. Furthermore, the correlations between normalized mcrA DNA abundance and the rumen fluid concentration of acetic and isobutyric acid were positive, whereas the correlations with propionic and lactic acid were negative. These data suggest that the mcrA DNA approach based on qmcrA primers could potentially be a molecular proxy for methane yield after further refinement. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Coal gasification systems engineering and analysis. Appendix C: Alternate product facility designs

NASA Technical Reports Server (NTRS)

1980-01-01

The study of the production of methane, methanol, gasoline, and hydrogen by an add-on facility to a Koppers-Totzek based MBG plant is presented. Applications to a Texaco facility are inferred by evaluation of delta effects from the K-T cases. The production of methane from an add-on facility to a Lurgi based MBG plant and the co-production of methane and methanol from a Lurgi based system is studied. Studies are included of the production of methane from up to 50 percent of the MBG produced in an integrated K-T based plant and the production of methane from up to 50 percent of the MBG produced from an integrated plant in which module 1 is based on K-T technology and modules 2, 3, and 4 are based on Texaco technology.

Theoretical Acoustic Absorber Design Approach for LOX/LCH4 Pintle Injector Rocket Engines

NASA Astrophysics Data System (ADS)

Candelaria, Jonathan

Liquid rocket engines, or LREs, have served a key role in space exploration efforts. One current effort involves the utilization of liquid oxygen (LOX) and liquid methane (LCH4) LREs to explore Mars with in-situ resource utilization for propellant production. This on-site production of propellant will allow for greater payload allocation instead of fuel to travel to the Mars surface, and refueling of propellants to travel back to Earth. More useable mass yields a greater benefit to cost ratio. The University of Texas at El Paso's (UTEP) Center for Space Exploration and Technology Research Center (cSETR) aims to further advance these methane propulsion systems with the development of two liquid methane - liquid oxygen propellant combination rocket engines. The design of rocket engines, specifically liquid rocket engines, is complex in that many variables are present that must be taken into consideration in the design. A problem that occurs in almost every rocket engine development program is combustion instability, or oscillatory combustion. It can result in the destruction of the rocket, subsequent destruction of the vehicle and compromise the mission. These combustion oscillations can vary in frequency from 100 to 20,000 Hz or more, with varying effects, and occur from different coupling phenomena. It is important to understand the effects of combustion instability, its physical manifestations, how to identify the instabilities, and how to mitigate or dampen them. Linear theory methods have been developed to provide a mathematical understanding of the low- to mid-range instabilities. Nonlinear theory is more complex and difficult to analyze mathematically, therefore no general analytical method that yields a solution exists. With limited resources, time, and the advice of our NASA mentors, a data driven experimental approach utilizing quarter wave acoustic dampener cavities was designed. This thesis outlines the methodology behind the design of an acoustic dampening system for a 500 lbf and a 2000 lbf throttleable liquid oxygen liquid methane pintle injector rocket engine.

Life cycle assessment to evaluate the environmental impact of biochar implementation in conservation agriculture in Zambia.

PubMed

Sparrevik, Magnus; Field, John L; Martinsen, Vegard; Breedveld, Gijs D; Cornelissen, Gerard

2013-02-05

Biochar amendment to soil is a potential technology for carbon storage and climate change mitigation. It may, in addition, be a valuable soil fertility enhancer for agricultural purposes in sandy and/or weathered soils. A life cycle assessment including ecological, health and resource impacts has been conducted for field sites in Zambia to evaluate the overall impacts of biochar for agricultural use. The life cycle impacts from conservation farming using cultivation growth basins and precision fertilization with and without biochar addition were in the present study compared to conventional agricultural methods. Three different biochar production methods were evaluated: traditional earth-mound kilns, improved retort kilns, and micro top-lit updraft (TLUD) gasifier stoves. The results confirm that the use of biochar in conservation farming is beneficial for climate change mitigation purposes. However, when including health impacts from particle emissions originating from biochar production, conservation farming plus biochar from earth-mound kilns generally results in a larger negative effect over the whole life cycle than conservation farming without biochar addition. The use of cleaner technologies such as retort kilns or TLUDs can overcome this problem, mainly because fewer particles and less volatile organic compounds, methane and carbon monoxide are emitted. These results emphasize the need for a holistic view on biochar use in agricultural systems. Of special importance is the biochar production technique which has to be evaluated from both environmental/climate, health and social perspectives.

NOVEL MEMBRANE PROCESS TO UTILIZE DILUTE METHANE STREAMS - PHASE II

EPA Science Inventory

Microbial electricity generation in rice paddy fields: recent advances and perspectives in rhizosphere microbial fuel cells.

PubMed

Kouzuma, Atsushi; Kaku, Nobuo; Watanabe, Kazuya

2014-12-01

Microbial fuel cells (MFCs) are devices that use living microbes for the conversion of organic matter into electricity. MFC systems can be applied to the generation of electricity at water/sediment interfaces in the environment, such as bay areas, wetlands, and rice paddy fields. Using these systems, electricity generation in paddy fields as high as ∼80 mW m(-2) (based on the projected anode area) has been demonstrated, and evidence suggests that rhizosphere microbes preferentially utilize organic exudates from rice roots for generating electricity. Phylogenetic and metagenomic analyses have been conducted to identify the microbial species and catabolic pathways that are involved in the conversion of root exudates into electricity, suggesting the importance of syntrophic interactions. In parallel, pot cultures of rice and other aquatic plants have been used for rhizosphere MFC experiments under controlled laboratory conditions. The findings from these studies have demonstrated the potential of electricity generation for mitigating methane emission from the rhizosphere. Notably, however, the presence of large amounts of organics in the rhizosphere drastically reduces the effect of electricity generation on methane production. Further studies are necessary to evaluate the potential of these systems for mitigating methane emission from rice paddy fields. We suggest that paddy-field MFCs represent a promising approach for harvesting latent energy of the natural world.

Waste lipids to energy: how to optimize methane production from long‐chain fatty acids (LCFA)

PubMed Central

Alves, M. Madalena; Pereira, M. Alcina; Sousa, Diana Z.; Cavaleiro, Ana J.; Picavet, Merijn; Smidt, Hauke; Stams, Alfons J. M.

2009-01-01

Summary The position of high‐rate anaerobic technology (HR‐AnWT) in the wastewater treatment and bioenergy market can be enhanced if the range of suitable substrates is expanded. Analyzing existing technologies, applications and problems, it is clear that, until now, wastewaters with high lipids content are not effectively treated by HR‐AnWT. Nevertheless, waste lipids are ideal potential substrates for biogas production, since theoretically more methane can be produced, when compared with proteins or carbohydrates. In this minireview, the classical problems of lipids methanization in anaerobic processes are discussed and new concepts to enhance lipids degradation are presented. Reactors operation, feeding strategies and prospects of technological developments for wastewater treatment are discussed. Long‐chain fatty acids (LCFA) degradation is accomplished by syntrophic communities of anaerobic bacteria and methanogenic archaea. For optimal performance these syntrophic communities need to be clustered in compact aggregates, which is often difficult to achieve with wastewaters that contain fats and lipids. Driving the methane production from lipids/LCFA at industrial scale without risk of overloading and inhibition is still a challenge that has the potential for filling a gap in the existing processes and technologies for biological methane production associated to waste and wastewater treatment. PMID:21255287

Comparison of physically- and economically-based CO2-equivalences for methane

NASA Astrophysics Data System (ADS)

Boucher, O.

2012-01-01

There is a controversy on the role methane (and other short-lived species) should play in climate mitigation policies and no consensus on what an optimal methane CO2-equivalence should be. We revisit this question by discussing the relative merits of physically-based (i.e. Global Warming Potential or GWP and Global Temperature change Potential or GTP) and socio-economically-based climate metrics. To this effect we use a simplified Global Damage Potential (GDP) that was introduced by earlier authors and investigate the uncertainties in the methane CO2-equivalence that arise from physical and socio-economic factors. The median value of the methane GDP comes out very close to the widely used methane 100-year GWP because of various compensating effects. However there is a large spread in possible methane CO2-equivalences (1-99% interval: 10.0-42.5; 5-95% interval: 12.5-38.0) that is essentially due to the choice in some socio-economic parameters (i.e. the damage cost function and the discount rate). The methane 100-year GTP falls outside these ranges. It is legitimate to increase the methane CO2-equivalence in the future as global warming unfolds. While changes in biogeochemical cycles and radiative efficiencies cause some small changes to physically-based metrics, a systematic increase in the methane CO2-equivalence can only be achieved by some ad-hoc shortening of the time horizon. In contrast using a convex damage cost function provides a natural increase in the methane CO2-equivalence for the socio-economically-based metrics. We also show that a methane CO2-equivalence based on a pulse emission is sufficient to inform multi-year climate policies and emissions reductions as long as there is some degree of visibility on CO2 prices and CO2-equivalences.

Vista-LA: Mapping methane-emitting infrastructure in the Los Angeles megacity

NASA Astrophysics Data System (ADS)

Carranza, Valerie; Rafiq, Talha; Frausto-Vicencio, Isis; Hopkins, Francesca M.; Verhulst, Kristal R.; Rao, Preeti; Duren, Riley M.; Miller, Charles E.

2018-03-01

Methane (CH4) is a potent greenhouse gas (GHG) and a critical target of climate mitigation efforts. However, actionable emission reduction efforts are complicated by large uncertainties in the methane budget on relevant scales. Here, we present Vista, a Geographic Information System (GIS)-based approach to map potential methane emissions sources in the South Coast Air Basin (SoCAB) that encompasses Los Angeles, an area with a dense, complex mixture of methane sources. The goal of this work is to provide a database that, together with atmospheric observations, improves methane emissions estimates in urban areas with complex infrastructure. We aggregated methane source location information into three sectors (energy, agriculture, and waste) following the frameworks used by the State of California GHG Inventory and the Intergovernmental Panel on Climate Change (IPCC) Guidelines for GHG Reporting. Geospatial modeling was applied to publicly available datasets to precisely geolocate facilities and infrastructure comprising major anthropogenic methane source sectors. The final database, Vista-Los Angeles (Vista-LA), is presented as maps of infrastructure known or expected to emit CH4. Vista-LA contains over 33 000 features concentrated on < 1 % of land area in the region. Currently, Vista-LA is used as a planning and analysis tool for atmospheric measurement surveys of methane sources, particularly for airborne remote sensing, and methane hotspot detection using regional observations. This study represents a first step towards developing an accurate, spatially resolved methane flux estimate for point sources in SoCAB, with the potential to address discrepancies between bottom-up and top-down methane emissions accounting in this region. The Vista-LA datasets and associated metadata are available from the Oak Ridge National Laboratory Distributed Active Archive Center for Biogeochemical Dynamics (ORNL DAAC; https://doi.org/10.3334/ORNLDAAC/1525).

Potential methane production and oxidation in soil reclamation covers of an oil sands mining site in Alberta, Canada

NASA Astrophysics Data System (ADS)

Pum, Lisa; Reichenauer, Thomas; Germida, Jim

2015-04-01

Anthropogenic activities create a number of significant greenhouse gases and thus potentially contribute to global warming. Methane production is significant in some agricultural production systems and from wetlands. In soil, methane can be oxidised by methanotrophic bacteria. However, little is known about methane production and oxidation in oil sand reclamation covers. The purpose of this study was to investigate methane production and oxidation potential of tailing sands and six different reclamation layers of oil sands mining sites in Alberta, Canada. Methane production and oxidation potential were investigated in laboratory scale microcosms through continuous headspace analysis using gas chromatography. Samples from a reclamation layer were collected at the Canadian Natural Resources Limited (CNRL) reclamation site at depths of 0-10 cm, 10-20 cm and 20-40 cm in October 2014. In addition, tailing sands provided by Suncor Energy Inc. and soil from a CNRL wetland were studied for methane production. Samples were dried, crushed and sieved to 4 mm, packed into serum bottle microcosms and monitored for eight weeks. Methane production potential was assessed by providing an anoxic environment and by adjusting the samples to a moisture holding capacity of 100 %. Methane oxidation potential was examined by an initial application of 2 vol % methane to the microcosms and by adjusting the samples to a moisture holding capacity of 50 %. Microcosm headspace gas was analysed for methane, carbon dioxide, nitrous oxide and oxygen. All experiments were carried out in triplicates, including controls. SF6 and Helium were used as internal standards to detect potential leaks. Our results show differences for methane production potential between the soil depths, tailing sands and wetlands. Moreover, there were differences in the methane oxidation potential of substrate from the three depths investigated and between the reclamation layers. In conclusion, the present study shows that reclamation layers for oil sands mining sites in Alberta, Canada have the potential to oxidize on-site produced methane emissions to the less harmful greenhouse gas carbon dioxide. Such oxidation might mitigate impacts of methane production from these sites.

Demonstration of Technologies for Remote and in Situ Sensing of Atmospheric Methane Abundances - a Controlled Release Experiment

NASA Astrophysics Data System (ADS)

Aubrey, A. D.; Thorpe, A. K.; Christensen, L. E.; Dinardo, S.; Frankenberg, C.; Rahn, T. A.; Dubey, M.

2013-12-01

It is critical to constrain both natural and anthropogenic sources of methane to better predict the impact on global climate change. Critical technologies for this assessment include those that can detect methane point and concentrated diffuse sources over large spatial scales. Airborne spectrometers can potentially fill this gap for large scale remote sensing of methane while in situ sensors, both ground-based and mounted on aerial platforms, can monitor and quantify at small to medium spatial scales. The Jet Propulsion Laboratory (JPL) and collaborators recently conducted a field test located near Casper, WY, at the Rocky Mountain Oilfield Test Center (RMOTC). These tests were focused on demonstrating the performance of remote and in situ sensors for quantification of point-sourced methane. A series of three controlled release points were setup at RMOTC and over the course of six experiment days, the point source flux rates were varied from 50 LPM to 2400 LPM (liters per minute). During these releases, in situ sensors measured real-time methane concentration from field towers (downwind from the release point) and using a small Unmanned Aerial System (sUAS) to characterize spatiotemporal variability of the plume structure. Concurrent with these methane point source controlled releases, airborne sensor overflights were conducted using three aircraft. The NASA Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) participated with a payload consisting of a Fourier Transform Spectrometer (FTS) and an in situ methane sensor. Two imaging spectrometers provided assessment of optical and thermal infrared detection of methane plumes. The AVIRIS-next generation (AVIRIS-ng) sensor has been demonstrated for detection of atmospheric methane in the short wave infrared region, specifically using the absorption features at ~2.3 μm. Detection of methane in the thermal infrared region was evaluated by flying the Hyperspectral Thermal Emission Spectrometer (HyTES), retrievals which interrogate spectral features in the 7.5 to 8.5 μm region. Here we discuss preliminary results from the JPL activities during the RMOTC controlled release experiment, including capabilities of airborne sensors for total columnar atmospheric methane detection and comparison to results from ground measurements and dispersion models. Potential application areas for these remote sensing technologies include assessment of anthropogenic and natural methane sources over wide spatial scales that represent significant unconstrained factors to the global methane budget.

Methane Post-Processor Development to Increase Oxygen Recovery beyond State-of-the-Art Carbon Dioxide Reduction Technology

NASA Technical Reports Server (NTRS)

Abney, Morgan; Miller, Lee; Greenwood, Zach; Iannantuono, Michelle; Jones, Kenny

2013-01-01

State-of-the-art life support carbon dioxide (CO2) reduction technology, based on the Sabatier reaction, is theoretically capable of 50% recovery of oxygen from metabolic CO2. This recovery is constrained by the limited availability of reactant hydrogen. Post-processing of the methane byproduct from the Sabatier reactor results in hydrogen recycle and a subsequent increase in oxygen recovery. For this purpose, a Methane Post-Processor Assembly containing three sub-systems has been developed and tested. The assembly includes a Methane Purification Assembly (MePA) to remove residual CO2 and water vapor from the Sabatier product stream, a Plasma Pyrolysis Assembly (PPA) to partially pyrolyze methane into hydrogen and acetylene, and an Acetylene Separation Assembly (ASepA) to purify the hydrogen product for recycle. The results of partially integrated testing of the sub-systems are reported.

Methane Post-Processor Development to Increase Oxygen Recovery beyond State-of-the-Art Carbon Dioxide Reduction Technology

NASA Technical Reports Server (NTRS)

Abney, Morgan B.; Greenwood, Zachary; Miller, Lee A.; Alvarez, Giraldo; Iannantuono, Michelle; Jones, Kenny

2013-01-01

State-of-the-art life support carbon dioxide (CO2) reduction technology, based on the Sabatier reaction, is theoretically capable of 50% recovery of oxygen from metabolic CO2. This recovery is constrained by the limited availability of reactant hydrogen. Post-processing of the methane byproduct from the Sabatier reactor results in hydrogen recycle and a subsequent increase in oxygen recovery. For this purpose, a Methane Post-Processor Assembly containing three sub-systems has been developed and tested. The assembly includes a Methane Purification Assembly (MePA) to remove residual CO2 and water vapor from the Sabatier product stream, a Plasma Pyrolysis Assembly (PPA) to partially pyrolyze methane into hydrogen and acetylene, and an Acetylene Separation Assembly (ASepA) to purify the hydrogen product for recycle. The results of partially integrated testing of the sub-systems are reported

Measuring the respiratory gas exchange of grazing cattle using the GreenFeed emissions monitoring system

USDA-ARS?s Scientific Manuscript database

Ruminants are a significant source of enteric methane, which has been identified as a powerful greenhouse gas that contributes to climate change. With interest in developing technologies to decrease enteric methane emission, systems are currently being developed to measure the methane emission by c...

Effect of coconut oil and defaunation treatment on methanogenesis in sheep.

PubMed

Machmüller, Andrea; Soliva, Carla R; Kreuzer, Michael

2003-01-01

The present study was conducted to evaluate in vivo the role of rumen ciliate protozoa with respect to the methane-suppressing effect of coconut oil. Three sheep were subjected to a 2 x 2 factorial design comprising two types of dietary lipids (50 g x kg(-1) coconut oil vs. 50 g x kg(-1) rumen-protected fat) and defaunation treatment (with vs. without). Due to the defaunation treatment, which reduced the rumen ciliate protozoa population by 94% on average, total tract fibre degradation was reduced but not the methane production. Feeding coconut oil significantly reduced daily methane release without negatively affecting the total tract nutrient digestion. Compared with the rumen-protected fat diet, coconut oil did not alter the energy retention of the animals. There was no interaction between coconut oil feeding and defaunation treatment in methane production. An interaction occurred in the concentration of methanogens in the rumen fluid, with the significantly highest values occurring when the animals received the coconut oil diet and were subjected to the defaunation treatment. Possible explanations for the apparent inconsistency between the amount of methane produced and the concentration of methane-producing microbes are discussed. Generally, the present data illustrate that a depression of the concentration of ciliate protozoa or methanogens in rumen fluid cannot be used as a reliable indicator for the success of a strategy to mitigate methane emission in vivo. The methane-suppressing effect of coconut oil seems to be mediated through a changed metabolic activity and/or composition of the rumen methanogenic population.

Variations in archaeal and bacterial diversity associated with the anaerobic oxidation of methane in the active mud volcanoes of the Canadian Beaufort Sea

NASA Astrophysics Data System (ADS)

Lee, Y. M.; Lee, D. H.; Hwang, K.; Hong, S. G.; Jin, Y. K.

2016-12-01

The prokaryotic microorganisms inhabiting Mud Volcanoes (MVs) play an important role for mitigation of methane (CH4) emission. Despite the identification of active MVs in the continental slope of the Canadian Beaufort Sea, little is known about the distribution and functions of prokaryotic community in this region. Hence, we investigated the prokaryotic diversity of four sediment cores (three from the active MVs and one from a non-methane influenced reference site) of the Canadian Beaufort Sea using 454-pyrosequencing of 16S rRNA genes as the first step to understand the prokaryotic roles in controlling outgassing methane. Bacterial and archaeal communities of MVs were distinctive from those of the reference site, and the communities of MVs were similar to each other at deeper depth levels. Chloroflexi, Actinobacteria, unclassified bacterial groups, and MCG_c of Crenarchaeota were predominant in the MVs, while Firmicutes, Deltaproteobacteria, and unclassified class of Thaumarchaeota were dominant in reference site. The relative abundance of dominant bacterial groups varied at sulfate-methane transition zone (SMTZ) of individual MVs. However, certain microbial taxa such as members of SAGMEG_o or Methanosarcinales of Euryarcheaota and Dehalococcoidales of Chloroflexi were predominant at SMTZs. Since they are not the classical representative taxa known to be involved in anaerobic oxidation of methane, their dominance implicates that they could be playing important roles in methane cycling using unrevealed mechanisms. We will further perform the phylogenetic and network analyses to infer mechanisms and interactions of dominant operational taxonomic units in controlling methane flux.

Methane emissions from the global oil and gas supply chain: recent advances and next steps

NASA Astrophysics Data System (ADS)

Zavala Araiza, D.; Herndon, S. C.; Roscioli, J. R.; Yacovitch, T. I.; Knighton, W. B.; Johnson, M.; Tyner, D. R.; Hamburg, S.

2017-12-01

A wide body of research has characterized methane emissions from the oil and gas system in the US. In contrast, empirical data is limited for other significant oil and gas producing regions across the world. As a consequence, measuring and characterizing methane emissions across global oil and gas operations will be crucial to the design of effective mitigation strategies. Several countries have announced pledges to reduce methane emissions from this system (e.g., North America, Climate and Clean Air Coalition [CCAC] ministers). In the case of Canada, the federal government recently announced regulations supporting a 40-45% reduction of methane emissions from the oil and gas production systems. For these regulations to be effective, it is critical to understand the current methane emission patterns. We present results from a coordinated multiscale (i.e., airborne-based, ground-based) measurement campaign in Alberta, Canada. We use empirically derived emission estimates to characterize site-level emissions and derive an emissions distribution. Our work shows that many major sources of emissions are unmeasured or underreported. Consistent with previous studies in the US, a small fraction of sites disproportionately account for the majority of emissions: roughly 20% of sites accounted for 75% of emissions. An independent airborne-based regional estimate was 40% lower than the ground-based regional estimate, but not statistically different. Finally, we summarize next steps as part of the CCAC Oil and Gas Methane Study: ongoing work that is targeting oil and gas sectors/production regions with limited empirical data on methane emissions. This work builds on the approach deployed in quantifying methane emissions from the oil and gas supply chain in the US, underscoring the commitment to transparency of the collected data, external review, deployment of multiple methodologies, and publication of results in peer-reviewed journals.

Hydrocarbon Development from Shale: A Set of Important, Unsolved Problems

NASA Astrophysics Data System (ADS)

Ingraffea, A. R.; Burchell, A.; Howarth, R.; Wilson, A.; Doe, P.; Colborn, T.; Wood, M. C.

2013-12-01

Hydraulic fracturing has become synonymous with the new technologies and processes used to develop oil and methane from shale formations. We will address the following important set of problems associated with such development and the role scientists are playing in communicating these to the public. Human Health Consequences: The health consequences of the wide-range of fugitive hydrocarbon emissions associated with methane and oil are not adequately addressed. New evidence about exposure to, and the known and possible health effects of, these toxic hitch hikers will be presented. Methane Emissions: Methane is a more powerful greenhouse gas than carbon dioxide, though atmospheric residence is shorter. Methane is emitted through-out the development life-cycle, albeit there is uncertainty over the rate, and short-term effect on global warming. Leakage from Faulty Wells: Multiple industry studies show that about 5 percent of oil and gas wells immediately leak methane and other fluids into the atmosphere and water wells due to integrity issues and increasing rates of leakage over time. With millions of wells drilled worldwide, and millions more expected, this problem is neither negligible nor preventable with current technology. Federal Exemptions and Home Rule: 'Fracking' currently slips through federal environmental statutory law because of an industry-friendly exemption. However, trusts are established in US law and the Public Trust Doctrine provides a basis for courts to enjoin 'fracking' due to the potential impact on beneficiaries of the trust --present and future generations. The public trust designates government as a trustee of crucial resources and imposes a fiduciary obligation on agencies to prevent "substantial impairment" of- and protect access to- clean air, clean water and other natural resources vital for public welfare and survival. Already applied to the realm of ecology, the doctrine is reviewed as a legal and policy toot to protect communities threatened by 'fracking.' Additionally, 'oil and gas - rights' Legislation and State Supreme Court decisions in communities underlain by shale deposits has been to silence 'Home-Rule' rights. The post-extraction impact of such rulings on public health and property values is dramatic. Soil Quality: Fracking poses a serious threat to soil quality and underlines the crucial role that soils can play in mitigating climate change. In addition to critical ecosystem and agricultural benefits, healthy soils represent a significant natural carbon reservoir. Enhancing the Natural Terrestrial Sequestration (NTS) potential of soils is an important carbon management strategy. Our studies reveal undisturbed soils underlain by intermediate to mafic volcanic rocks and shale formations sampled can have 2 to 6 times greater total organic soil carbon (TOSC) than global averages. However, anthropogenic disturbed-lands now represent the 7th largest- land class (ISRIC, US-DOI) and may account for a significant reduction in NTS potential. EPA studies indicate 20 to 85% of frack-fluids are not recovered. This could continue to be a long-term source of soil and groundwater contamination - risking further decreased NTS potential.

Hydrogen generator, via catalytic partial oxidation of methane for fuel cells

NASA Astrophysics Data System (ADS)

Recupero, Vincenzo; Pino, Lidia; Di Leonardo, Raffaele; Lagana', Massimo; Maggio, Gaetano

It is well known that the most acknowledged process for generation of hydrogen for fuel cells is based upon the steam reforming of methane or natural gas. A valid alternative could be a process based on partial oxidation of methane, since the process is mildly exothermic and therefore not energy intensive. Consequently, great interest is expected from conversion of methane into syngas, if an autothermal, low energy intensive, compact and reliable process could be developed. This paper covers the activities, performed by the CNR Institute of Transformation and Storage of Energy (CNR-TAE), on theoretical and experimental studies for a compact hydrogen generator, via catalytic selective partial oxidation of methane, integrated with second generation fuel cells (EC-JOU2 contract). In particular, the project focuses the attention on methane partial oxidation via heterogeneous selective catalysts, in order to: demonstrate the basic catalytic selective partial oxidation of methane (CSPOM) technology in a subscale prototype, equivalent to a nominal output of 5 kWe; develop the CSPOM technology for its application in electric energy production by means of fuel cells; assess, by a balance of plant analysis, and a techno-economic evaluation, the potential benefits of the CSPOM for different categories of fuel cells.

Methane Leak Rates from Natural Gas Wells in Norther California

NASA Astrophysics Data System (ADS)

Cui, Y.; Yoon, S.; Chen, Y.; Falk, M.; Kuwayama, T.; Croes, B. E.; Herner, J.; Vijayan, A.

2017-12-01

Methane is a potent greenhouse gas (GHG) and is the second most prevalent GHG emitted in California from human activities. As part of a comprehensive effort to reduce GHG emissions and meet the statewide climate goals, California has proposed a Short Lived Climate Pollutant (SLCP) Strategy that includes a 40% reduction of methane emissions from 2013 levels by 2030, with goals to reduce oil and gas related emissions and capture methane emissions from dairy operations and organic waste. There is growing evidence in the recent scientific literature suggesting that methane emissions can come from every stage of the oil and gas supply chain. During oil and gas production operations, studies reported that a small number of oil and gas wells made up a large fraction of total methane emissions from the wells. In such a fat-tail distribution, the mean methane leak rate from wells is orders of magnitude larger than the median, which indicates the presence of super emitter sources. However, since the super emitters are often positioned as outliers in a fat-tail distribution and do not always behave consistently, measuring their leak rates is challenging, but critical to quantify their impacts and identify potential mitigation opportunities. This presentation will discuss of methane leak rates measured from natural gas wells in Northern California for different well operations: active, idle, and plugged. The leak rates demonstrated fat-tail distributions, and the mean leak rates for each well operation status were an order of magnitude higher than the median leak rates. It was also observed that roughly 20% of wells contributed more than 80% of methane emissions. Further data collection is needed with a larger number of samples to better understand the relationship between the leak rates and well operation status. Such measurements could help improve the estimate of methane emissions from natural gas wells and inform methane reduction policies and programs in California.

Characterization of methane emissions from five cold heavy oil production with sands (CHOPS) facilities.

PubMed

Roscioli, Joseph R; Herndon, Scott C; Yacovitch, Tara I; Knighton, W Berk; Zavala-Araiza, Daniel; Johnson, Matthew R; Tyner, David R

2018-03-07

Cold heavy oil production with sands (CHOPS) is a common oil extraction method in the Canadian provinces of Alberta and Saskatchewan that can result in significant methane emissions due to annular venting. Little is known about the magnitude of these emissions, nor their contributions to the regional methane budget. Here the authors present the results of field measurements of methane emissions from CHOPS wells and compare them with self-reported venting rates. The tracer ratio method was used not only to analyze total site emissions but at one site it was also used to locate primary emission sources and quantify their contributions to the facility-wide emission rate, revealing the annular vent to be a dominant source. Emissions measured from five different CHOPS sites in Alberta showed large discrepancies between the measured and reported rates, with emissions being mainly underreported. These methane emission rates are placed in the context of current reporting procedures and the role that gas-oil ratio (GOR) measurements play in vented volume estimates. In addition to methane, emissions of higher hydrocarbons were also measured; a chemical "fingerprint" associated with CHOPS wells in this region reveals very low emission ratios of ethane, propane, and aromatics versus methane. The results of this study may inform future studies of CHOPS sites and aid in developing policy to mitigate regional methane emissions. Methane measurements from cold heavy oil production with sand (CHOPS) sites identify annular venting to be a potentially major source of emissions at these facilities. The measured emission rates are generally larger than reported by operators, with uncertainty in the gas-oil ratio (GOR) possibly playing a large role in this discrepancy. These results have potential policy implications for reducing methane emissions in Alberta in order to achieve the Canadian government's goal of reducing methane emissions by 40-45% below 2012 levels within 8 yr.

Emissions Benefits From Renewable Fuels and Other Alternatives for Heavy-Duty Vehicles

NASA Astrophysics Data System (ADS)

Hajbabaei, Maryam

There is a global effort to expand the use of alternative fuels due to their several benefits such as improving air quality with reducing some criteria emissions, reducing dependency on fossil fuels, and reducing greenhouse gases such as carbon dioxide. This dissertation is focused on investigating the impact of two popular alternative fuels, biodiesel and natural gas (NG), on emissions from heavy-duty engines. Biodiesel is one of the most popular renewable fuels with diesel applications. Although biodiesel blends are reported to reduce particulate matter, carbon monoxide, and total hydrocarbon emissions; there is uncertainty on their impact on nitrogen oxides (NOx) emissions. This dissertation evaluated the effect of biodiesel feedstock, biodiesel blend level, engine technology, and driving conditions on NOx emissions. The results showed that NOx emissions increase with 20% and higher biodiesel blends. Also, in this study some strategies were proposed and some fuel formulations were found for mitigating NOx emissions increases with biodiesel. The impact of 5% biodiesel on criteria emissions specifically NOx was also fully studied in this thesis. As a part of the results of this study, 5% animal-based biodiesel was certified for use in California based on California Air Resources Board emissions equivalent procedure. NG is one of the most prominent alternative fuels with larger reserves compared to crude oil. However, the quality of NG depends on both its source and the degree to which it is processed. The current study explored the impact of various NG fuels, ranging from low methane/high energy gases to high methane/low energy gases, on criteria and toxic emissions from NG engines with different combustion and aftertreatment technologies. The results showed stronger fuel effects for the lean-burn technology bus. Finally, this thesis investigated the impact of changing diesel fuel composition on the criteria emissions from a variety of heavy-duty engine technologies. Emissions from an average diesel fuel used throughout the U.S. were compared with a 10% aromatic, ultra-low sulfur diesel fuel used in California with more stringent air quality regulations. The results showed that the emerging aftertreatment technologies eventually eliminate the benefits of the lower aromatic content/higher cetane number diesel fuels.

Physical properties of hydrate‐bearing sediments

USGS Publications Warehouse

Waite, William F.; Santamarina, J.C.; Cortes, D.D.; Dugan, Brandon; Espinoza, D.N.; Germaine, J.; Jang, J.; Jung, J.W.; Kneafsey, T.J.; Shin, H.; Soga, K.; Winters, William J.; Yun, T.S.

2009-01-01

Methane gas hydrates, crystalline inclusion compounds formed from methane and water, are found in marine continental margin and permafrost sediments worldwide. This article reviews the current understanding of phenomena involved in gas hydrate formation and the physical properties of hydrate‐bearing sediments. Formation phenomena include pore‐scale habit, solubility, spatial variability, and host sediment aggregate properties. Physical properties include thermal properties, permeability, electrical conductivity and permittivity, small‐strain elastic P and S wave velocities, shear strength, and volume changes resulting from hydrate dissociation. The magnitudes and interdependencies of these properties are critically important for predicting and quantifying macroscale responses of hydrate‐bearing sediments to changes in mechanical, thermal, or chemical boundary conditions. These predictions are vital for mitigating borehole, local, and regional slope stability hazards; optimizing recovery techniques for extracting methane from hydrate‐bearing sediments or sequestering carbon dioxide in gas hydrate; and evaluating the role of gas hydrate in the global carbon cycle.

Effects of essential oils from medicinal plants acclimated to Benin on in vitro ruminal fermentation of Andropogon gayanus grass.

PubMed

Kouazounde, Jacques B; Jin, Long; Assogba, Fidele M; Ayedoun, Marc A; Wang, Yuxi; Beauchemin, Karen A; McAllister, Tim A; Gbenou, Joachim D

2015-03-30

Plants from West Africa commonly used in both human and veterinary medicine contain various secondary metabolites. However, their potential in mitigating ruminal methane production has not been explored. This study examined the effects of seven essential oils (EOs) from plants acclimated to Benin at four dosages (100, 200, 300 and 400 mg L(-1)), on in vitro rumen microbial fermentation and methane production using Andropogon gayanus grass as a substrate. Compared to control, Laurus nobilis (300-400 mg L(-1) ), Citrus aurantifolia (300-400 mg L(-1)) and Ocimum gratissimum (200-400 mg L(-1)) decreased (P < 0.05) methane production (mL g(-1) DM) by 8.1-11.8%, 11.9-17.8% and 7.9-30.6%, respectively. Relative to the control, reductions in methane (mL g(-1) DM) of 11.4%, 13.5% and 14.2% were only observed at 400 mg L(-1) for Eucalyptus citriodora, Ocimum basilicum and Cymbopogon citratus, respectively. These EOs lowered methane without reducing concentrations of total volatile fatty acids or causing a shift from acetate to propionate production. All EOs (except M. piperita) reduced (P < 0.05) apparent dry matter (DM) disappearance of A. gayanus. The current study demonstrated that EOs from plants grown in Benin inhibited in vitro methane production mainly through a reduction in apparent DM digestibility. © 2014 Society of Chemical Industry.

Effects of mineral salt supplement on enteric methane emissions, ruminal fermentation and methanogen community of lactating cows.

PubMed

Li, Xiaohua; Liu, Chong; Chen, Yongxing; Shi, Rongguang; Cheng, Zhenhua; Dong, Hongmin

2017-08-01

We evaluated the effects of mineral salt supplement on enteric methane emissions, ruminal fermentation and methanogen community of dairy cows over a whole lactation period. Ten Holstein cows fed a total mixed ration (TMR) diet were randomly allocated into two groups, one supplied with mineral salts as the treatment group and the other as the control group. The methane measurement showed that the ingestion of mineral salts lowered enteric methane emissions significantly (P < 0.05), with an average of 10.5% reduction over the whole lactation period. Ruminal fermentation analysis showed the mineral salt intake could significantly decrease the acetate : propionate ratio (P < 0.05). Real-time PCR assay showed that rumen methanogen abundance significantly reduced in the treatment group (P < 0.05) but was not significantly influenced by mineral salt intake over the whole lactation period. Intergroup methanogen community composition was influenced slightly by mineral salt intake; however, significantly different intragroup profiles were apparent throughout the whole lactation period, according to denaturing gradient gel electrophoresis analysis. In conclusion, these results suggested that the effective mitigation of enteric methane emissions by mineral salt intake could be attributed to decreased density of methanogenic archaea and that fluctuations in methane emission over the lactation period might be related to Methanobrevibacter diversity. © 2016 Japanese Society of Animal Science.

Aging well: methanotrophic potential and community structure along a paddy soil chronosequence of 2000 years.

NASA Astrophysics Data System (ADS)

Ho, Adrian; Frenzel, Peter

2010-05-01

Given that rice paddies are anthropogenic methane sources and the inevitable need to increase rice production to sustain human population growth, it is pertinent to identify the effects of long term agriculture on the selection of methanotrophs. Methanotrophs play a crucial role in mitigating methane emission from rice paddies. Therefore, we analyzed the methanotroph community along a chronosequence of paddy soils from China covering recently reclaimed sites to paddies under permanent agriculture since 2000 years (Cheng et al., 2009; doi:10.1016/j.geoderma.2009.03.016). Maximum potential methane oxidation rate (PMOR) increased monotonically with age. Our results also showed that long-term agriculture imposes a selection pressure on different groups of methanotrophs. In contrast to younger soils, type Ib methanotrophs were observed to multiply in correspondence with increasing PMOR in ancient soils, while other groups showed a relatively stable community composition as revealed by pmoA-based fingerprints (T-RFLP) and quantitative PCR. Cloning and sequencing the pmoA (a key gene in methane oxidation), the soils were found to harbour known and putative methanotrophs, ammonium-oxidizing bacteria, and interestingly, sequences affiliated to Crenothrix, a methane oxidizer with an unusual pmoA (Stoecker et al., 2006; doi:10.1073/pnas.0506361103). In summary, long-term agriculture shapes the community and allows for an elevated level of potential methane oxidation.

Geoscience research helps rice farmers mitigate climate change and world hunger

NASA Astrophysics Data System (ADS)

Runkle, B.; Suvocarev, K.; Reba, M. L.

2017-12-01

Rice is a globally important crop - it comprises 30% of total human caloric consumption - and will be an important crop in the face of expanding population growth. Unfortunately, it is often grown in flooded paddies whose swampy conditions allow microbes to produce the strong greenhouse gas, methane. Over 10% of anthropogenic methane emission to the atmosphere are attributed to rice cultivation. Fortunately, a water-saving irrigation method known as Alternate Wetting and Drying can reduce methane emissions by periodically drying the soil. In our experiments, the method has no effect on rice harvest yields. In our research with rice farmers in Arkansas, we work to evaluate the amount of methane reductions on different fields with this irrigation practice. This research aims to expand the scientific basis for carbon emission reductions programs that enable farmers to be paid for implementing this practice. There are still gaps in our knowledge about how much methane is produced and under what conditions. Our research involves the continuous detection of field methane emissions and correlates then to changes in environmental conditions like the height and temperature of paddy water. Understanding these relationships may help more farmers qualify for credits in the growing carbon emission reductions programs. Because many farmers are already collecting information about their irrigation practices to reduce water applications, we aim to help them re-use this data to more quickly qualify for carbon emissions reductions payments.

Latest on Mobile Methane Measurements with Fast Open-Path Technology: Experiences, Opportunities & Perspectives

NASA Astrophysics Data System (ADS)

Burba, George; Anderson, Tyler; Ediger, Kevin; von Fischer, Joseph; Gioli, Beniamino; Ham, Jay; Hupp, Jason; Kohnert, Katrin; Larmanou, Eric; Levy, Peter; Polidori, Andrea; Pikelnaya, Olga; Price, Eric; Sachs, Torsten; Serafimovich, Andrei; Zondlo, Mark; Zulueta, Rommel

2016-04-01

Methane plays a critical role in the radiation balance, chemistry of the atmosphere, and air quality. The major sources of methane include agricultural and natural production, landfill emissions, oil and gas development sites, and natural gas distribution networks in rural and urban environments. The majority of agricultural and natural methane production occurs in areas with little infrastructure or easily available grid power (e.g., rice fields, arctic and boreal wetlands, tropical mangroves, etc.) Past approaches for direct measurements of methane fluxes relied on fast closed-path analyzers, which typically require powerful pumps and grid power. Power and labor demands may be among the key reasons why such methane fluxes were often measured at locations with good infrastructure and grid power, and not necessarily with high methane production. Landfill methane emissions were traditionally assessed via point-in-time measurements taken at monthly or longer time intervals using techniques such as the trace plume method, the mass balance method, etc. These are subject to large uncertainties because of the snapshot nature of the measurements, while the changes in emission rates are continuous due to ongoing landfill development, changes in management practices, and the barometric pumping phenomenon. Installing a continuously operating flux station in the middle of an active landfill requires a low-power approach with no cables stretching across the landfill. The majority of oil and gas and urban methane emission happens via variable-rate point sources or diffused spots in topographically challenging terrains, such as street tunnels, elevated locations at water treatment plants, vents, etc. Locating and measuring methane emissions from such sources is challenging when using traditional micrometeorological techniques, and requires development of novel approaches. In 2010, a new lightweight high-speed high-resolution open-path technology was developed with the goal of allowing eddy covariance measurements of methane flux with power consumption 30-150 times below other available technologies. The instrumentation was designed to run on solar panels or a small generator, and could be placed in the middle of the methane-producing ecosystem without a need for grid power. This significantly expanded the methane flux measurement coverage in permafrost regions, wetlands, rice fields and landfills. In the past few years, this instrumentation has been utilized increasingly more frequently outside of the traditional use at stationary flux towers. The novel approaches included measurements from various moving platforms, such as cars, aircraft, and ships. Projects included mapping of concentrations and vertical profiles, leak detection and quantification, mobile emission detection from natural gas cars, soil methane flux surveys, etc. This presentation will describe key developmental steps in the lightweight low-power high-resolution open-path technology, the instrument principles and key elements of the design, and will highlight several novel approaches where such instrumentation was used in mobile deployments in urban and natural environments.

Increased Oxygen Recovery from Sabatier Systems Using Plasma Pyrolysis Technology and Metal Hydride Separation

NASA Technical Reports Server (NTRS)

Greenwood, Zachary W.; Abney, Morgan B.; Perry, Jay L.; Miller, Lee A.; Dahl, Roger W.; Hadley, Neal M.; Wambolt, Spencer R.; Wheeler, Richard R.

2015-01-01

State-of-the-art life support carbon dioxide (CO2) reduction technology is based on the Sabatier reaction where less than 50% of the oxygen required for the crew is recovered from metabolic CO2. The reaction produces water as the primary product and methane as a byproduct. Oxygen recovery is constrained by the limited availability of reactant hydrogen. This is further exacerbated when Sabatier methane (CH4) is vented as a waste product resulting in a continuous loss of reactant hydrogen. Post-processing methane with the Plasma Pyrolysis Assembly (PPA) to recover hydrogen has the potential to dramatically increase oxygen recovery and thus drastically reduce the logistical challenges associated with oxygen resupply. The PPA decomposes methane into predominantly hydrogen and acetylene. Due to the highly unstable nature of acetylene, a separation system is necessary to purify hydrogen before it is recycled back to the Sabatier reactor. Testing and evaluation of a full-scale Third Generation PPA is reported and investigations into metal hydride hydrogen separation technology is discussed.

Natural Gas STAR Program

EPA Pesticide Factsheets

EPA’s Voluntary Methane Programs encourage oil and natural gas companies to adopt cost-effective technologies and practices that improve operational efficiency and reduce emissions of methane, a potent greenhouse gas.

Effects of diet and manure storage method on carbon and nitrogen dynamics during storage and plant nitrogen uptake

USDA-ARS?s Scientific Manuscript database

Altering dairy cattle diets to reduce both enteric methane (CH4) production and nitrogen (N) excretion are valuable tools for mitigating the environmental impact of dairy production. We examined the impact of altering diets on changes in physicochemical properties of manure during storage, short ter...

Can southern US rice cultivars be used to mitigate greenhouse gas emissions? A preliminary study.

USDA-ARS?s Scientific Manuscript database

Most rice in the world is produced under flooded paddy conditions as a means of producing high stable yields and controlling non-aquatic weeds. However, the anaerobic soil conditions that occur as a result of the flooded fields cause high levels of methane production due to bacterial methanogenesis....

The importance of determining carbon sequestration and greenhouse gas mitigation potential in ornamental horticulture

USDA-ARS?s Scientific Manuscript database

Over the past three decades, one issue which has received significant attention from the scientific community is climate change and the possible impacts on the global environment. Increased atmospheric carbon dioxide (CO2) concentration, along with other trace gases [i.e., methane (CH4) and nitrous ...

Laboratory evaluation of surface amendments for controlling greenhouse gas emissions from beef cattle feedlots.

USDA-ARS?s Scientific Manuscript database

Pen surface amendments for mitigating emissions of greenhouse gases (GHGs), such as nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2), from beef cattle feedlots, were evaluated under controlled laboratory conditions. Amendments were organic residues (i.e., sorghum straw, prairie grass, wo...

Using rice genetic diversity for adaptions to and mitigation of changing environments

USDA-ARS?s Scientific Manuscript database

Human activities are contributing to greenhouse gas emissions and predictions are that atmospheric CO2 levels will double by the end of the century. Methane, the second most abundant greenhouse gas, is ~25 times more potent in global warming potential than carbon dioxide, and 7-17% of atmospheric me...

Reducing emissions from agriculture to meet the 2 °C target.

PubMed

Wollenberg, Eva; Richards, Meryl; Smith, Pete; Havlík, Petr; Obersteiner, Michael; Tubiello, Francesco N; Herold, Martin; Gerber, Pierre; Carter, Sarah; Reisinger, Andrew; van Vuuren, Detlef P; Dickie, Amy; Neufeldt, Henry; Sander, Björn O; Wassmann, Reiner; Sommer, Rolf; Amonette, James E; Falcucci, Alessandra; Herrero, Mario; Opio, Carolyn; Roman-Cuesta, Rosa Maria; Stehfest, Elke; Westhoek, Henk; Ortiz-Monasterio, Ivan; Sapkota, Tek; Rufino, Mariana C; Thornton, Philip K; Verchot, Louis; West, Paul C; Soussana, Jean-François; Baedeker, Tobias; Sadler, Marc; Vermeulen, Sonja; Campbell, Bruce M

2016-12-01

More than 100 countries pledged to reduce agricultural greenhouse gas (GHG) emissions in the 2015 Paris Agreement of the United Nations Framework Convention on Climate Change. Yet technical information about how much mitigation is needed in the sector vs. how much is feasible remains poor. We identify a preliminary global target for reducing emissions from agriculture of ~1 GtCO 2 e yr -1 by 2030 to limit warming in 2100 to 2 °C above pre-industrial levels. Yet plausible agricultural development pathways with mitigation cobenefits deliver only 21-40% of needed mitigation. The target indicates that more transformative technical and policy options will be needed, such as methane inhibitors and finance for new practices. A more comprehensive target for the 2 °C limit should be developed to include soil carbon and agriculture-related mitigation options. Excluding agricultural emissions from mitigation targets and plans will increase the cost of mitigation in other sectors or reduce the feasibility of meeting the 2 °C limit. © 2016 The Authors Global Change Biology Published by John Wiley & Sons Ltd.

Liquid Methane Conditioning Capabilities Developed at the NASA Glenn Research Center's Small Multi- Purpose Research Facility (SMiRF) for Accelerated Lunar Surface Storage Thermal Testing

NASA Technical Reports Server (NTRS)

Bamberger, Helmut H.; Robinson, R. Craig; Jurns, John M.; Grasl, Steven J.

2011-01-01

Glenn Research Center s Creek Road Cryogenic Complex, Small Multi-Purpose Research Facility (SMiRF) recently completed validation / checkout testing of a new liquid methane delivery system and liquid methane (LCH4) conditioning system. Facility checkout validation was conducted in preparation for a series of passive thermal control technology tests planned at SMiRF in FY10 using a flight-like propellant tank at simulated thermal environments from 140 to 350K. These tests will validate models and provide high quality data to support consideration of LCH4/LO2 propellant combination option for a lunar or planetary ascent stage.An infrastructure has been put in place which will support testing of large amounts of liquid methane at SMiRF. Extensive modifications were made to the test facility s existing liquid hydrogen system for compatibility with liquid methane. Also, a new liquid methane fluid conditioning system will enable liquid methane to be quickly densified (sub-cooled below normal boiling point) and to be quickly reheated to saturation conditions between 92 and 140 K. Fluid temperatures can be quickly adjusted to compress the overall test duration. A detailed trade study was conducted to determine an appropriate technique to liquid conditioning with regard to the SMiRF facility s existing infrastructure. In addition, a completely new roadable dewar has been procured for transportation and temporary storage of liquid methane. A new spherical, flight-representative tank has also been fabricated for integration into the vacuum chamber at SMiRF. The addition of this system to SMiRF marks the first time a large-scale liquid methane propellant test capability has been realized at Glenn.This work supports the Cryogenic Fluid Management Project being conducted under the auspices of the Exploration Technology Development Program, providing focused cryogenic fluid management technology efforts to support NASA s future robotic or human exploration missions.

A novel free ammonia based pretreatment technology to enhance anaerobic methane production from primary sludge.

PubMed

Wei, Wei; Zhou, Xu; Xie, Guo-Jun; Duan, Haoran; Wang, Qilin

2017-10-01

This study proposed a novel free ammonia (FA, i.e., NH 3 ) pretreatment technology to enhance anaerobic methane production from primary sludge for the first time. The solubilization of primary sludge was substantially enhanced following 24 h FA pretreatment (250-680 mg NH 3 -N/L), by which the release of soluble chemical oxygen demand (SCOD) (i.e., 0.4 mg SCOD/mg VS added; VS: volatile solids) was approximately 10 times as much as that without pretreatment (i.e., 0.03 mg SCOD/mg VS added). Then, biochemical methane potential (BMP) tests demonstrated that FA pretreatment of 250-680 mg NH 3 -N/L was capable of enhancing anaerobic methane production while the digestion time was more than 7 days. Model based analysis indicated that the improved anaerobic methane production was due to an increased biochemical methane potential (B 0 ) of 8-17% (i.e., from 331 to 357-387 L CH 4 /kg VS added), with the highest B 0 achieved at 420 mg NH 3 -N/L pretreatment. However, FA pretreatment of 250-680 mg NH 3 -N/L decreased hydrolysis rate (k) by 24-38% compared with control (i.e., from 0.29 d -1 to 0.18-0.22 d -1 ), which explained the lower methane production over the first 7 days' digestion period. Economic analysis and environmental evaluation demonstrated that FA pretreatment technology was environmentally friendly and economically favorable. Biotechnol. Bioeng. 2017;114: 2245-2252. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Process for separating nitrogen from methane using microchannel process technology

DOEpatents

Tonkovich, Anna Lee [Marysville, OH; Qiu, Dongming [Dublin, OH; Dritz, Terence Andrew [Worthington, OH; Neagle, Paul [Westerville, OH; Litt, Robert Dwayne [Westerville, OH; Arora, Ravi [Dublin, OH; Lamont, Michael Jay [Hilliard, OH; Pagnotto, Kristina M [Cincinnati, OH

2007-07-31

The disclosed invention relates to a process for separating methane or nitrogen from a fluid mixture comprising methane and nitrogen, the process comprising: (A) flowing the fluid mixture into a microchannel separator, the microchannel separator comprising a plurality of process microchannels containing a sorption medium, the fluid mixture being maintained in the microchannel separator until at least part of the methane or nitrogen is sorbed by the sorption medium, and removing non-sorbed parts of the fluid mixture from the microchannel separator; and (B) desorbing the methane or nitrogen from the sorption medium and removing the desorbed methane or nitrogen from the microchannel separator. The process is suitable for upgrading methane from coal mines, landfills, and other sub-quality sources.

The winter gap effect in methane leak detection and repair with optical gas imaging cameras

NASA Astrophysics Data System (ADS)

Fox, T. A.; Barchyn, T.; Hugenholtz, C.

2017-12-01

Implementing effective leak detection and repair (LDAR) programs is essential for mitigating fugitive methane emissions from oil and gas operations. In Canada, newly proposed regulations will require that high-risk facilities be surveyed 3 times/yr for fugitive leaks. Like the United States, Canada promotes the use of Optical Gas Imaging cameras (OGIs) for detecting natural gas leaks during LDAR surveys. However, recent research suggests OGIs may perform poorly under adverse environmental conditions, especially in low temperatures. For regions like Canada that experience cold winters, OGIs may not be reliably used for months at a time, meaning that leaks may accumulate and emit for longer periods before being repaired. While considerable oil and gas activity occurs in high-latitude regions with cold winters, no research has explored how extended cold periods impact OGI-focused LDAR programs. To improve this understanding, we present a simple model exploring relationships among winter gap length, fugitive methane emissions, and investment input for LDAR programs employing OGI instruments in gas producing regions of different latitudes. Preliminary results suggest that longer gaps between LDAR surveys caused by cold temperatures result in either 1) higher total emissions for the year, or 2) greater time and equipment investment in LDAR programs to achieve emissions mitigation equivalent to LDAR programs operating under ideal conditions. When weather constraints are removed and LDAR surveys are evenly spaced throughout the year, emissions mitigation is optimized. However, as the winter gap duration and the size of the implicated area increases, fugitive leaks last longer. Furthermore, a spillover effect is observed as LDAR crews become overwhelmed with the high volume of work required as temperatures increase in the spring. Our model adds weight to the argument that LDAR programs should be tailored to regional needs, and that regulators should be more cognisant of sensor-specific limitations as they develop LDAR protocols.

Methane drainage with horizontal boreholes in advance of longwall mining: an analysis. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gabello, D.P.; Felts, L.L.; Hayoz, F.P.

1981-05-01

The US Department of Energy (DOE) Morgantown Energy Technology Center has implemented a comprehensive program to demonstrate the technical and economic viability of coalbed methane as an energy resource. The program is directed toward solution of technical and institutional problems impeding the recovery and use of large quantities of methane contained in the nation's minable and unminable coalbeds. Conducted in direct support of the DOE Methane Recovery from Coalbeds Project, this study analyzes the economic aspects of a horizontal borehole methane recovery system integrated as part of a longwall mine operation. It establishes relationships between methane selling price and annualmore » mine production, methane production rate, and the methane drainage system capital investment. Results are encouraging, indicating that an annual coal production increase of approximately eight percent would offset all associated drainage costs over the range of methane production rates and capital investments considered.« less

Anthropogenic Methane Emissions in California's San Joaquin Valley: Characterizing Large Point Source Emitters

NASA Astrophysics Data System (ADS)

Hopkins, F. M.; Duren, R. M.; Miller, C. E.; Aubrey, A. D.; Falk, M.; Holland, L.; Hook, S. J.; Hulley, G. C.; Johnson, W. R.; Kuai, L.; Kuwayama, T.; Lin, J. C.; Thorpe, A. K.; Worden, J. R.; Lauvaux, T.; Jeong, S.; Fischer, M. L.

2015-12-01

Methane is an important atmospheric pollutant that contributes to global warming and tropospheric ozone production. Methane mitigation could reduce near term climate change and improve air quality, but is hindered by a lack of knowledge of anthropogenic methane sources. Recent work has shown that methane emissions are not evenly distributed in space, or across emission sources, suggesting that a large fraction of anthropogenic methane comes from a few "super-emitters." We studied the distribution of super-emitters in California's southern San Joaquin Valley, where elevated levels of atmospheric CH4 have also been observed from space. Here, we define super-emitters as methane plumes that could be reliably detected (i.e., plume observed more than once in the same location) under varying wind conditions by airborne thermal infrared remote sensing. The detection limit for this technique was determined to be 4.5 kg CH4 h-1 by a controlled release experiment, corresponding to column methane enhancement at the point of emissions greater than 20% above local background levels. We surveyed a major oil production field, and an area with a high concentration of large dairies using a variety of airborne and ground-based measurements. Repeated airborne surveys (n=4) with the Hyperspectral Thermal Emission Spectrometer revealed 28 persistent methane plumes emanating from oil field infrastructure, including tanks, wells, and processing facilities. The likelihood that a given source type was a super-emitter varied from roughly 1/3 for processing facilities to 1/3000 for oil wells. 11 persistent plumes were detected in the dairy area, and all were associated with wet manure management. The majority (11/14) of manure lagoons in the study area were super-emitters. Comparing to a California methane emissions inventory for the surveyed areas, we estimate that super-emitters comprise a minimum of 9% of inventoried dairy emissions, and 13% of inventoried oil emissions in this region.

Incentives for methane mitigation and energy-efficiency improvements in the case of Ukraine's natural gas transmission system

NASA Astrophysics Data System (ADS)

Roshchanka, Volha; Evans, Meredydd

2014-06-01

Reducing methane losses is a concern for climate change policy and energy policy. The energy sector is the major source of anthropogenic methane emissions into the atmosphere in Ukraine. Reducing methane emissions and avoiding combustion can be very cost-effective, but various barriers prevent such energy-efficiency measures from taking place. To date, few examples of industry-wide improvements exist. One example of substantial investments into upgrading natural gas transmission system comes from Ukraine's natural gas transmission company, Ukrtransgaz. The company's investments into system upgrades, along with a 34% fall in throughput, resulted in reduction of Ukrtransgaz system's own consumption of natural gas by 68% in 2011 compared to the level in 2005. Evaluating reductions in methane emissions is challenging because of lack of accurate data and gaps in accounting methodologies. At the same time, Ukraine's transmission system has undergone improvements that, at the very least, have contained methane emissions, if not substantially reduced them. In this paper, we describe recent developments in Ukraine's natural gas transmission system and analyze the incentives that forced the sector to pay close attention to its methane losses. Ukraine is one of the most energy-intensive countries, among the largest natural gas consumers in the world, and a significant emitter of methane. The country is also dependent on imports of natural gas. A combination of several factors has created conditions for successful reductions in methane emissions and combustion. These factors include: an eightfold increase in the price of imported natural gas; comprehensive domestic environmental and energy policies, such as the Laws of Ukraine on Protecting the Natural Environment and on Air Protection; policies aimed at integration with European Union's energy market and accession to the Energy Community Treaty; and the country's participation in international cooperation on environment, such as through the Joint Implementation mechanism and the voluntary Global Methane Initiative. Learning about such case studies can help policymakers and sustainability professionals design better policies elsewhere.

The Soil Microbial Response to a Massive Natural Gas Leak

NASA Astrophysics Data System (ADS)

Tavormina, P. L.; Newman, S.; Shen, L.; Connon, S. A.; Okumura, M.; Orphan, V. J.

2016-12-01

The 2015/2016 gas leak in the Porter Ranch community (Southern California) was the largest natural gas leak in US history. While considerable attention has focused on the amount of methane released to the atmosphere and the effects of other gas components on human well-being, less attention has been given to the response of soil microbes to this event. These microbes represent natural pathways for utilization of C1 compounds in soils and, possibly, untapped potential to remediate natural and anthropogenic gas emissions. We monitored onsite and background soil methane concentrations and microbial communities during and following the Porter Ranch gas leak. Soil core samples (25cm depth, collected twice monthly beginning in January 2016) were preserved for DNA, RNA, microscopic, stable isotope probing, and chromatographic methods. Simultaneously to coring, gas from soil pore spaces was collected for cavity ringdown spectroscopy to measure carbon dioxide, methane and ethane concentrations, and estimate corresponding isotopic values in carbon dioxide and methane. By pairing these measurements with high throughput sequencing, transcript analysis, and cultivation, we demonstrate discrete shifts in the total microbial community in surface (0 - 5 cm) and deep (20 - 25 cm) soils. Importantly, we find that methane consumption likely occurred in surface soils during and following the leak. The lineages most significantly correlated with elevated methane from the leak event were five orders of magnitude more abundant near the leak event in space and time, indicating a microbial bloom. These lineages are previously unrecognized members of Sphingomonadaceae, and they encode at least two biochemical pathways for methane oxidation. Cultivation of the first representative of this group now allows more detailed investigation into its capacity for microbially-mediated soil methane oxidation and mitigation.

The German collaborative project SUGAR Utilization of a natural treasure - Developing innovative techniques for the exploration and production of natural gas from hydrate-bearing sediments

NASA Astrophysics Data System (ADS)

Haeckel, M.; Bialas, J.; Wallmann, K. J.

2009-12-01

Gas hydrates occur in nature at all active and passive continental margins as well as in permafrost regions, and vast amounts of natural gas are bound in those deposits. Geologists estimate that twice as much carbon is bound in gas hydrates than in any other fossil fuel reservoir, such as gas, oil and coal. Hence, natural gas hydrates represent a huge potential energy resource that, in addition, could be utilized in a CO2-neutral and therefore environmentally friendly manner. However, the utilization of this natural treasure is not as easy as the conventional production of oil or natural gas and calls for new and innovative techniques. In the framework of the large-scale collaborative research project SUGAR (Submarine Deposits of Gas Hydrates - Exploration, Production and Transportation), we aim to produce gas from methane hydrates and to sequester carbon dioxide from power plants and other industrial sources as CO2 hydrates in the same host sediments. Thus, the SUGAR project addresses two of the most pressing and challenging topics of our time: development of alternative energy strategies and greenhouse gas mitigation techniques. The SUGAR project is funded by two federal German ministries and the German industry for an initial period of three years. In the framework of this project new technologies starting from gas hydrate exploration techniques over drilling technologies and innovative gas production methods to CO2 storage in gas hydrates and gas transportation technologies will be developed and tested. Beside the performance of experiments, numerical simulation studies will generate data regarding the methane production and CO2 sequestration in the natural environment. Reservoir modelling with respect to gas hydrate formation and development of migration pathways complete the project. This contribution will give detailed information about the planned project parts and first results with focus on the production methods.

Catalytic conversion of methane to methanol using Cu-zeolites.

PubMed

Alayon, Evalyn Mae C; Nachtegaal, Maarten; Ranocchiari, Marco; van Bokhoven, Jeroen A

2012-01-01

The conversion of methane to value-added liquid chemicals is a promising answer to the imminent demand for fuels and chemical synthesis materials in the advent of a dwindling petroleum supply. Current technology requires high energy input for the synthesis gas production, and is characterized by low overall selectivity, which calls for alternative reaction routes. The limitation to achieve high selectivity is the high C-H bond strength of methane. High-temperature reaction systems favor gas-phase radical reactions and total oxidation. This suggests that the catalysts for methane activation should be active at low temperatures. The enzymatic-inspired metal-exchanged zeolite systems apparently fulfill this need, however, methanol yield is low and a catalytic process cannot yet be established. Homogeneous and heterogeneous catalytic systems have been described which stabilize the intermediate formed after the first C-H activation. The understanding of the reaction mechanism and the determination of the active metal sites are important for formulating strategies for the upgrade of methane conversion catalytic technologies.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Byrer, C.W.; Layne, A.W.; Guthrie, H.D.

The U.S. Department of Energy (DOE), at its Morgantown Energy Technology Center, has been involved in natural gas research since the 1970`s. DOE has assessed the potential of gas in coals throughout the U.S. and promoted research and development for recovery and use of methane found in minable and unminable coalbeds. DOE efforts have focused on the use of coal mine methane for regional economic gas self-sufficiency, energy parks, self-help initiatives, and small-power generation. This paper focuses on DOE`s past and present efforts to more effectively and efficiently recover and use this valuable domestic energy source. The Climate Change Actionmore » Plan (CCAP) (1) lists a series of 50 voluntary initiatives designed to reduce greenhouse gas emissions, such as methane from mining operations, to their 1990 levels. Action No. 36 of the CCAP expands the DOE research, development, and demonstration (RD&D) efforts to broaden the range of cost-effective technologies and practices for recovering methane associated with coal mining operations. The major thrust of Action No. 36 is to reduce methane emissions associated with coal mining operations from target year 2000 levels by 1.5 MMT of carbon equivalent. Crosscutting activities in the DOE Natural Gas Program supply the utilization sectors will address RD&D to reduce methane emissions released from various mining operations, focusing on recovery and end use technology systems to effectively drain, capture, and utilize the emitted gas. Pilot projects with industry partners will develop and test the most effective methods and technology systems for economic recovery and utilization of coal mine gas emissions in regions where industry considers efforts to be presently non-economic. These existing RD&D programs focus on near-term gas recovery and gathering systems, gas upgrading, and power generation.« less

Facultative methanotrophs are abundant at terrestrial natural gas seeps.

PubMed

Farhan Ul Haque, Muhammad; Crombie, Andrew T; Ensminger, Scott A; Baciu, Calin; Murrell, J Colin

2018-06-28

Natural gas contains methane and the gaseous alkanes ethane, propane and butane, which collectively influence atmospheric chemistry and cause global warming. Methane-oxidising bacteria, methanotrophs, are crucial in mitigating emissions of methane as they oxidise most of the methane produced in soils and the subsurface before it reaches the atmosphere. Methanotrophs are usually obligate, i.e. grow only on methane and not on longer chain alkanes. Bacteria that grow on the other gaseous alkanes in natural gas such as propane have also been characterised, but they do not grow on methane. Recently, it was shown that the facultative methanotroph Methylocella silvestris grew on ethane and propane, other components of natural gas, in addition to methane. Therefore, we hypothesised that Methylocella may be prevalent at natural gas seeps and might play a major role in consuming all components of this potent greenhouse gas mixture before it is released to the atmosphere. Environments known to be exposed to biogenic methane emissions or thermogenic natural gas seeps were surveyed for methanotrophs. 16S rRNA gene amplicon sequencing revealed that Methylocella were the most abundant methanotrophs in natural gas seep environments. New Methylocella-specific molecular tools targeting mmoX (encoding the soluble methane monooxygenase) by PCR and Illumina amplicon sequencing were designed and used to investigate various sites. Functional gene-based assays confirmed that Methylocella were present in all of the natural gas seep sites tested here. This might be due to its ability to use methane and other short chain alkane components of natural gas. We also observed the abundance of Methylocella in other environments exposed to biogenic methane, suggesting that Methylocella has been overlooked in the past as previous ecological studies of methanotrophs often used pmoA (encoding the alpha subunit of particulate methane monooxygenase) as a marker gene. New biomolecular tools designed in this study have expanded our ability to detect, and our knowledge of the environmental distribution of Methylocella, a unique facultative methanotroph. This study has revealed that Methylocella are particularly abundant at natural gas seeps and may play a significant role in biogeochemical cycling of gaseous hydrocarbons.

Gene and transcript abundances of bacterial type III secretion systems from the rumen microbiome are correlated with methane yield in sheep.

PubMed

Kamke, Janine; Soni, Priya; Li, Yang; Ganesh, Siva; Kelly, William J; Leahy, Sinead C; Shi, Weibing; Froula, Jeff; Rubin, Edward M; Attwood, Graeme T

2017-08-08

Ruminants are important contributors to global methane emissions via microbial fermentation in their reticulo-rumens. This study is part of a larger program, characterising the rumen microbiomes of sheep which vary naturally in methane yield (g CH 4 /kg DM/day) and aims to define differences in microbial communities, and in gene and transcript abundances that can explain the animal methane phenotype. Rumen microbiome metagenomic and metatranscriptomic data were analysed by Gene Set Enrichment, sparse partial least squares regression and the Wilcoxon Rank Sum test to estimate correlations between specific KEGG bacterial pathways/genes and high methane yield in sheep. KEGG genes enriched in high methane yield sheep were reassembled from raw reads and existing contigs and analysed by MEGAN to predict their phylogenetic origin. Protein coding sequences from Succinivibrio dextrinosolvens strains were analysed using Effective DB to predict bacterial type III secreted proteins. The effect of S. dextrinosolvens strain H5 growth on methane formation by rumen methanogens was explored using co-cultures. Detailed analysis of the rumen microbiomes of high methane yield sheep shows that gene and transcript abundances of bacterial type III secretion system genes are positively correlated with methane yield in sheep. Most of the bacterial type III secretion system genes could not be assigned to a particular bacterial group, but several genes were affiliated with the genus Succinivibrio, and searches of bacterial genome sequences found that strains of S. dextrinosolvens were part of a small group of rumen bacteria that encode this type of secretion system. In co-culture experiments, S. dextrinosolvens strain H5 showed a growth-enhancing effect on a methanogen belonging to the order Methanomassiliicoccales, and inhibition of a representative of the Methanobrevibacter gottschalkii clade. This is the first report of bacterial type III secretion system genes being associated with high methane emissions in ruminants, and identifies these secretions systems as potential new targets for methane mitigation research. The effects of S. dextrinosolvens on the growth of rumen methanogens in co-cultures indicate that bacteria-methanogen interactions are important modulators of methane production in ruminant animals.

A new approach to evaluate regional methane emission from irrigated rice paddies: Combining process study, modeling and remote sensing into GIS

NASA Astrophysics Data System (ADS)

Ding, Aiju

2000-10-01

A large seasonal variation in methane emission from Texas rice fields was observed in most of the growing seasons from 1989 through 1997. In general, the pattern showed small fluxes in the early season of cultivation and reached maximum at post-heading time, then declined and stopped after fields were drained. The amount of methane emission positively relates to the aboveground biomass, the number of effective stems and tillers, and nitrogen addition. The day-to-day pattern of methane emissions was similar among all cultivars. The seasonal total methane emission shows a significant positive correlation with post-heading plant height. The total methane emission from Texas rice fields was estimated as 33.25 × 109 g in 1993, ranging from 25.85 × 109 g/yr to 40.65 × 109 g/yr. A mitigation technique was developed to obtain both high yield and less methane emission from Texas rice fields. A new approach was also developed to evaluate regional to large-scale methane emission from irrigated rice paddies. By combining modeling, ground truth information and remote sensing into a Geographic Information System (GIS)-a computer based system, the seasonal methane emission from a large area can be calculated efficiently and more accurately. The methodology was tested at the Richmond Irrigation District (RID) site in Texas. The average daily methane emission varied from field to field and even within a single field. The calculated seasonal total methane emission from RID rice fields was as low as 3.34 × 108 g CH4 in 1996 and as high as 7.80 × 108 g CH4 in 1998. To support the application of the estimation method in a worldwide study, an algorithm describing the mapping of irrigated rice paddies from Landsat TM data was demonstrated. The accuracy in 1998- supervised classification approached 95% when cloud cover was taken into account. Model uncertainty and data availability are the two major potential problems in worldwide application of the new approach. A potential alternative model is proposed which allows estimation of regional methane emission from rice plant height.

Reconciling Top-Down and Bottom-Up Estimates of Oil and Gas Methane Emissions in the Barnett Shale

NASA Astrophysics Data System (ADS)

Hamburg, S.

2015-12-01

Top-down approaches that use aircraft, tower, or satellite-based measurements of well-mixed air to quantify regional methane emissions have typically estimated higher emissions from the natural gas supply chain when compared to bottom-up inventories. A coordinated research campaign in October 2013 used simultaneous top-down and bottom-up approaches to quantify total and fossil methane emissions in the Barnett Shale region of Texas. Research teams have published individual results including aircraft mass-balance estimates of regional emissions and a bottom-up, 25-county region spatially-resolved inventory. This work synthesizes data from the campaign to directly compare top-down and bottom-up estimates. A new analytical approach uses statistical estimators to integrate facility emission rate distributions from unbiased and targeted high emission site datasets, which more rigorously incorporates the fat-tail of skewed distributions to estimate regional emissions of well pads, compressor stations, and processing plants. The updated spatially-resolved inventory was used to estimate total and fossil methane emissions from spatial domains that match seven individual aircraft mass balance flights. Source apportionment of top-down emissions between fossil and biogenic methane was corroborated with two independent analyses of methane and ethane ratios. Reconciling top-down and bottom-up estimates of fossil methane emissions leads to more accurate assessment of natural gas supply chain emission rates and the relative contribution of high emission sites. These results increase our confidence in our understanding of the climate impacts of natural gas relative to more carbon-intensive fossil fuels and the potential effectiveness of mitigation strategies.

Prediction of future methane emission from irrigated rice paddies in central Thailand under different water management practices.

PubMed

Minamikawa, Kazunori; Fumoto, Tamon; Iizumi, Toshichika; Cha-Un, Nittaya; Pimple, Uday; Nishimori, Motoki; Ishigooka, Yasushi; Kuwagata, Tsuneo

2016-10-01

There is concern about positive feedbacks between climate change and methane (CH4) emission from rice paddies. However, appropriate water management may mitigate the problem. We tested this hypothesis at six field sites in central Thailand, where the irrigated area is rapidly increasing. We used DNDC-Rice, a process-based biogeochemistry model adjusted based on rice growth data at each site to simulate CH4 emission from a rice-rice double cropping system from 2001 to 2060. Future climate change scenarios consisting of four representative concentration pathways (RCPs) and seven global climate models were generated by statistical downscaling. We then simulated CH4 emission in three water management practices: continuous flooding (CF), single aeration (SA), and multiple aeration (MA). The adjusted model reproduced the observed rice yield and CH4 emission well at each site. The simulated CH4 emissions in CF from 2051 to 2060 were 5.3 to 7.8%, 9.6 to 16.0%, 7.3 to 18.0%, and 13.6 to 19.0% higher than those from 2001 to 2010 in RCPs 2.6, 4.5, 6.0, and 8.5, respectively, at the six sites. Regionally, SA and MA mitigated CH4 emission by 21.9 to 22.9% and 53.5 to 55.2%, respectively, relative to CF among the four RCPs. These mitigation potentials by SA and MA were comparable to those from 2001 to 2010. Our results indicate that climate change in the next several decades will not attenuate the quantitative effect of water management practices on mitigating CH4 emission from irrigated rice paddies in central Thailand. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of dietary tannin source on performance, feed efficiency, ruminal fermentation, and carcass and non-carcass traits in steers fed a high-grain diet

USDA-ARS?s Scientific Manuscript database

Tannins are polyphenolic secondary plant compounds that have been shown to affect microbial activity to impact fermentation, protein degradation, methane production, and potential to mitigate foodborne pathogens. This study was conducted to examine the effects of source of tannin (condensed, CT, vs....

Free ammonia pre-treatment of secondary sludge significantly increases anaerobic methane production.

PubMed

Wei, Wei; Zhou, Xu; Wang, Dongbo; Sun, Jing; Wang, Qilin

2017-07-01

Energy recovery in the form of methane from sludge/wastewater is restricted by the poor and slow biodegradability of secondary sludge. An innovative pre-treatment technology using free ammonia (FA, i.e. NH 3 ) was proposed in this study to increase anaerobic methane production. The solubilisation of secondary sludge was significantly increased after FA pre-treatment at up to 680 mg NH 3 -N/L for 1 day, under which the solubilisation (i.e. 0.4 mg SCOD/mg VS; SCOD: soluble chemical oxygen demand; VS: volatile solids) was >10 times higher than that without FA pre-treatment (i.e. 0.03 mg SCOD/mg VS). Biochemical methane potential assays showed that FA pre-treatment at above 250 mg NH 3 -N/L is effective in improving anaerobic methane production. The highest improvement in biochemical methane potential (B 0 ) and hydrolysis rate (k) was achieved at FA concentrations of 420-680 mg NH 3 -N/L, and was determined as approximately 22% (from 160 to 195 L CH 4 /kg VS added) and 140% (from 0.22 to 0.53 d -1 ) compared to the secondary sludge without pre-treatment. More analysis revealed that the FA induced improvement in B 0 and k could be attributed to the rapidly biodegradable substances rather than the slowly biodegradable substances. Economic and environmental analyses showed that the FA-based technology is economically favourable and environmentally friendly. Since this FA technology aims to use the wastewater treatment plants (WWTPs) waste (i.e. anaerobic digestion liquor) to enhance methane production from the WWTPs, it will set an example for the paradigm shift of the WWTPs from 'linear economy' to 'circular economy'. Copyright © 2017 Elsevier Ltd. All rights reserved.

ELECTROCHEMISTRY AND ON-CELL REFORMATION MODELING FOR SOLID OXIDE FUEL CELL STACKS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Recknagle, Kurtis P.; Jarboe, Daniel T.; Johnson, Kenneth I.

2007-01-16

ABSTRACT Providing adequate and efficient cooling schemes for solid-oxide-fuel-cell (SOFC) stacks continues to be a challenge coincident with the development of larger, more powerful stacks. The endothermic steam-methane reformation reaction can provide cooling and improved system efficiency when performed directly on the electrochemically active anode. Rapid kinetics of the endothermic reaction typically causes a localized temperature depression on the anode near the fuel inlet. It is desirable to extend the endothermic effect over more of the cell area and mitigate the associated differences in temperature on the cell to alleviate subsequent thermal stresses. In this study, modeling tools validated formore » the prediction of fuel use, on-cell methane reforming, and the distribution of temperature within SOFC stacks, are employed to provide direction for modifying the catalytic activity of anode materials to control the methane conversion rate. Improvements in thermal management that can be achieved through on-cell reforming is predicted and discussed. Two operating scenarios are considered: one in which the methane fuel is fully pre-reformed, and another in which a substantial percentage of the methane is reformed on-cell. For the latter, a range of catalytic activity is considered and the predicted thermal effects on the cell are presented. Simulations of the cell electrochemical and thermal performance with and without on-cell reforming, including structural analyses, show a substantial decrease in thermal stresses for an on-cell reforming case with slowed methane conversion.« less

Influence of methane in CO2 transport and storage for CCS technology.

PubMed

Blanco, Sofía T; Rivas, Clara; Fernández, Javier; Artal, Manuela; Velasco, Inmaculada

2012-12-04

CO(2) Capture and Storage (CCS) is a good strategy to mitigate levels of atmospheric greenhouse gases. The type and quantity of impurities influence the properties and behavior of the anthropogenic CO(2), and so must be considered in the design and operation of CCS technology facilities. Their study is necessary for CO(2) transport and storage, and to develop theoretical models for specific engineering applications to CCS technology. In this work we determined the influence of CH(4), an important impurity of anthropogenic CO(2), within different steps of CCS technology: transport, injection, and geological storage. For this, we obtained new pressure-density-temperature (PρT) and vapor-liquid equilibrium (VLE) experimental data for six CO(2) + CH(4) mixtures at compositions which represent emissions from the main sources in the European Union and United States. The P and T ranges studied are within those estimated for CO(2) pipelines and geological storage sites. From these data we evaluated the minimal pressures for transport, regarding the density and pipeline's capacity requirements, and values for the solubility parameter of the mixtures, a factor which governs the solubility of substances present in the reservoir before injection. We concluded that the presence of CH(4) reduces the storage capacity and increases the buoyancy of the CO(2) plume, which diminishes the efficiency of solubility and residual trapping of CO(2), and reduces the injectivity into geological formations.

76 FR 44581 - Agency Information Collection Activities; Submission to OMB for Review and Approval; Comment...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-26

... for reducing methane emissions. By joining, Natural Gas STAR partners agree to implement cost-effective technologies and practices to reduce methane emissions, which will save money, improve operational...

Assessment of the methane oxidation capacity of compacted soils intended for use as landfill cover materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rachor, Ingke, E-mail: i.rachor@ifb.uni-hamburg.de; Gebert, Julia; Groengroeft, Alexander

2011-05-15

The microbial oxidation of methane in engineered cover soils is considered a potent option for the mitigation of emissions from old landfills or sites containing wastes of low methane generation rates. A laboratory column study was conducted in order to derive design criteria that enable construction of an effective methane oxidising cover from the range of soils that are available to the landfill operator. Therefore, the methane oxidation capacity of different soils was assessed under simulated landfill conditions. Five sandy potential landfill top cover materials with varying contents of silt and clay were investigated with respect to methane oxidation andmore » corresponding soil gas composition over a period of four months. The soils were compacted to 95% of their specific proctor density, resulting in bulk densities of 1.4-1.7 g cm{sup -3}, reflecting considerably unfavourable conditions for methane oxidation due to reduced air-filled porosity. The soil water content was adjusted to field capacity, resulting in water contents ranging from 16.2 to 48.5 vol.%. The investigated inlet fluxes ranged from 25 to about 100 g CH{sub 4} m{sup -2} d{sup -1}, covering the methane load proposed to allow for complete oxidation in landfill covers under Western European climate conditions and hence being suggested as a criterion for release from aftercare. The vertical distribution of gas concentrations, methane flux balances as well as stable carbon isotope studies allowed for clear process identifications. Higher inlet fluxes led to a reduction of the aerated zone, an increase in the absolute methane oxidation rate and a decline of the relative proportion of oxidized methane. For each material, a specific maximum oxidation rate was determined, which varied between 20 and 95 g CH{sub 4} m{sup -2} d{sup -1} and which was positively correlated to the air-filled porosity of the soil. Methane oxidation efficiencies and gas profile data imply a strong link between oxidation capacity and diffusive ingress of atmospheric air. For one material with elevated levels of fine particles and high organic matter content, methane production impeded the quantification of methane oxidation potentials. Regarding the design of landfill cover layers it was concluded that the magnitude of the expected methane load, the texture and expected compaction of the cover material are key variables that need to be known. Based on these, a column study can serve as an appropriate testing system to determine the methane oxidation capacity of a soil intended as landfill cover material.« less

Satellite-derived methane hotspot emission estimates using a fast data-driven method

NASA Astrophysics Data System (ADS)

Buchwitz, Michael; Schneising, Oliver; Reuter, Maximilian; Heymann, Jens; Krautwurst, Sven; Bovensmann, Heinrich; Burrows, John P.; Boesch, Hartmut; Parker, Robert J.; Somkuti, Peter; Detmers, Rob G.; Hasekamp, Otto P.; Aben, Ilse; Butz, André; Frankenberg, Christian; Turner, Alexander J.

2017-05-01

Methane is an important atmospheric greenhouse gas and an adequate understanding of its emission sources is needed for climate change assessments, predictions, and the development and verification of emission mitigation strategies. Satellite retrievals of near-surface-sensitive column-averaged dry-air mole fractions of atmospheric methane, i.e. XCH4, can be used to quantify methane emissions. Maps of time-averaged satellite-derived XCH4 show regionally elevated methane over several methane source regions. In order to obtain methane emissions of these source regions we use a simple and fast data-driven method to estimate annual methane emissions and corresponding 1σ uncertainties directly from maps of annually averaged satellite XCH4. From theoretical considerations we expect that our method tends to underestimate emissions. When applying our method to high-resolution atmospheric methane simulations, we typically find agreement within the uncertainty range of our method (often 100 %) but also find that our method tends to underestimate emissions by typically about 40 %. To what extent these findings are model dependent needs to be assessed. We apply our method to an ensemble of satellite XCH4 data products consisting of two products from SCIAMACHY/ENVISAT and two products from TANSO-FTS/GOSAT covering the time period 2003-2014. We obtain annual emissions of four source areas: Four Corners in the south-western USA, the southern part of Central Valley, California, Azerbaijan, and Turkmenistan. We find that our estimated emissions are in good agreement with independently derived estimates for Four Corners and Azerbaijan. For the Central Valley and Turkmenistan our estimated annual emissions are higher compared to the EDGAR v4.2 anthropogenic emission inventory. For Turkmenistan we find on average about 50 % higher emissions with our annual emission uncertainty estimates overlapping with the EDGAR emissions. For the region around Bakersfield in the Central Valley we find a factor of 5-8 higher emissions compared to EDGAR, albeit with large uncertainty. Major methane emission sources in this region are oil/gas and livestock. Our findings corroborate recently published studies based on aircraft and satellite measurements and new bottom-up estimates reporting significantly underestimated methane emissions of oil/gas and/or livestock in this area in EDGAR.

The Atmospheres of Directly Imaged Planets: Where Has All the Methane Gone?

NASA Technical Reports Server (NTRS)

Marley, Mark S.; Zahnle, Kevin

2014-01-01

Methane and ammonia both first appear at lower effective temperatures in brown dwarf atmospheres than equilibrium chemistry models would suggest. This has traditionally been understood as a consequence of vertical mixing timescales being shorter than chemical equilibration timescales in brown dwarf photospheres. Indeed the eddy diffusivity, a variable accounting for the vigor of vertical mixing, has become a standard part of the description of brown dwarf atmosphere models, along with Teff and log g. While some models have suggested that methane is less favored at lower gravity, the almost complete absence of methane in the atmospheres of directly imaged planets, such as those orbiting HR 8799, even at effective temperatures where methane is readily apparent in brown dwarf spectra, has been puzzling. To better understand the paucity of methane in low gravity atmospheres we have revisited the problem of methane chemistry and mixing. We employed a 1-D atmospheric chemistry code augmented with an updated and complete network of the chemical reactions that link CO to CH4. We find the methane abundance at altitudes at or above the effective photosphere is a strong function of surface gravity because higher g shifts the p-T structure to higher pressures (i.e., a given optical depth is proportional to p/g, a relation mitigated somewhat by pressure broadening). Thus quenching in more massive brown dwarfs occurs at a lower temperature and higher pressure, both favoring CH4. We predict that in the lowest mass young giant planets, methane will appear very late, at effective temperatures as low as 600 K rather than the 1200 K seen among field brown dwarfs. This methane deficiency has important implications for the interpretation of spectra as well as methane-based planetary companion searches, such as the NICI survey. The GPI and SPHERE surveys will test these ideas and probe atmospheric chemistry and composition in an entire new range of parameter space. A caveat is that these calculations presume that the C to O ratio is comfortably less than one; the behavior is quite different if C and O are equally abundant, and of course CH4 is always present if C exceeds O.

Effects of low oxygen concentrations on aerobic methane oxidation in seasonally hypoxic coastal waters

NASA Astrophysics Data System (ADS)

Steinle, Lea; Maltby, Johanna; Treude, Tina; Kock, Annette; Bange, Hermann W.; Engbersen, Nadine; Zopfi, Jakob; Lehmann, Moritz F.; Niemann, Helge

2017-03-01

Coastal seas may account for more than 75 % of global oceanic methane emissions. There, methane is mainly produced microbially in anoxic sediments from which it can escape to the overlying water column. Aerobic methane oxidation (MOx) in the water column acts as a biological filter, reducing the amount of methane that eventually evades to the atmosphere. The efficiency of the MOx filter is potentially controlled by the availability of dissolved methane and oxygen, as well as temperature, salinity, and hydrographic dynamics, and all of these factors undergo strong temporal fluctuations in coastal ecosystems. In order to elucidate the key environmental controls, specifically the effect of oxygen availability, on MOx in a seasonally stratified and hypoxic coastal marine setting, we conducted a 2-year time-series study with measurements of MOx and physico-chemical water column parameters in a coastal inlet in the south-western Baltic Sea (Eckernförde Bay). We found that MOx rates generally increased toward the seafloor, but were not directly linked to methane concentrations. MOx exhibited a strong seasonal variability, with maximum rates (up to 11.6 nmol L-1 d-1) during summer stratification when oxygen concentrations were lowest and bottom-water temperatures were highest. Under these conditions, 2.4-19.0 times more methane was oxidized than emitted to the atmosphere, whereas about the same amount was consumed and emitted during the mixed and oxygenated periods. Laboratory experiments with manipulated oxygen concentrations in the range of 0.2-220 µmol L-1 revealed a submicromolar oxygen optimum for MOx at the study site. In contrast, the fraction of methane-carbon incorporation into the bacterial biomass (compared to the total amount of oxidized methane) was up to 38-fold higher at saturated oxygen concentrations, suggesting a different partitioning of catabolic and anabolic processes under oxygen-replete and oxygen-starved conditions, respectively. Our results underscore the importance of MOx in mitigating methane emission from coastal waters and indicate an organism-level adaptation of the water column methanotrophs to hypoxic conditions.

Inversion Estimate of California Methane Emissions Using a Bayesian Inverse Model with Multi-Tower Greenhouse Gas Monitoring Network and Aircraft Measurements

NASA Astrophysics Data System (ADS)

Cui, Y.; Falk, M.; Chen, Y.; Herner, J.; Croes, B. E.; Vijayan, A.

2017-12-01

Methane (CH4) is an important short-lived climate pollutant (SLCP), and the second most important greenhouse gas (GHG) in California which accounts for 9% of the statewide GHG emissions inventory. Over the years, California has enacted several ambitious climate change mitigation goals, including the California Global Warming Solutions Act of 2006 which requires ARB to reduce statewide GHG emissions to 1990 emission level by 2020, as well as Assembly Bill 1383 which requires implementation of a climate mitigation program to reduce statewide methane emissions by 40% below the 2013 levels. In order to meet these requirements, ARB has proposed a comprehensive SLCP Strategy with goals to reduce oil and gas related emissions and capture methane emissions from dairy operations and organic waste. Achieving these goals will require accurate understanding of the sources of CH4 emissions. Since direct monitoring of CH4 emission sources in large spatial and temporal scales is challenging and resource intensive, we developed a complex inverse technique combined with atmospheric three-dimensional (3D) transport model and atmospheric observations of CH4 concentrations from a regional tower network and aircraft measurements, to gain insights into emission sources in California. In this study, develop a comprehensive inversion estimate using available aircraft measurements from CalNex airborne campaigns (May-June 2010) and three years of hourly continuous measurements from the ARB Statewide GHG Monitoring Network (2014-2016). The inversion analysis is conducted using two independent 3D Lagrangian models (WRF-STILT and WRF-FLEXPART), with a variety of bottom-up prior inputs from national and regional inventories, as well as two different probability density functions (Gaussian and Lognormal). Altogether, our analysis provides a detailed picture of the spatially resolved CH4 emission sources and their temporal variation over a multi-year period.

Comparing Top-down and Bottom-up Estimates of Methane Emissions across Multiple U.S. Basins Provides Insights into National Oil and Gas Emissions and Mitigation Strategies

NASA Astrophysics Data System (ADS)

Hamburg, S.; Alvarez, R.; Lyon, D. R.; Zavala-Araiza, D.

2016-12-01

Several recent studies quantified regional methane emissions in U.S. oil and gas (O&G) basins using top-down approaches such as airborne mass balance measurements. These studies apportioned total methane emissions to O&G based on hydrocarbon ratios or subtracting bottom-up estimates of other sources. In most studies, top-down estimates of O&G methane emissions exceeded bottom-up emission inventories. An exception is the Barnett Shale Coordinated Campaign, which found agreement between aircraft mass balance estimates and a custom emission inventory. Reconciliation of Barnett Shale O&G emissions depended on two key features: 1) matching the spatial domains of top-down and bottom-up estimates, and 2) accounting for fat-tail sources in site-level emission factors. We construct spatially explicit custom emission inventories for domains with top-down O&G emission estimates in eight major U.S. oil and gas production basins using a variety of data sources including a spatially-allocated U.S. EPA Greenhouse Gas Inventory, the EPA Greenhouse Gas Reporting Program, state emission inventories, and recently published measurement studies. A comparison of top-down and our bottom-up estimates of O&G emissions constrains the gap between these approaches and elucidates regional variability in production-normalized loss rates. A comparison of component-level and site-level emission estimates of production sites in the Barnett Shale region - where comprehensive activity data and emissions estimates are available - indicates that abnormal process conditions contribute about 20% of regional O&G emissions. Combining these two analyses provides insights into the relative importance of different equipment, processes, and malfunctions to emissions in each basin. These data allow us to estimate the U.S. O&G supply chain loss rate, recommend mitigation strategies to reduce emissions from existing infrastructure, and discuss how a similar approach can be applied internationally.

Ginkgo fruit extract as an additive to modify rumen microbiota and fermentation and to mitigate methane production.

PubMed

Oh, S; Shintani, R; Koike, S; Kobayashi, Y

2017-03-01

Ginkgo fruit, an unused byproduct of the ginkgo nut industry, contains antimicrobial compounds known as anacardic acids. Two major cultivars of ginkgo, Kyuju (K) and Tokuro (T), were evaluated for their potential as a feed additive for ruminants. In batch culture, we incubated a mixture of hay and concentrate in diluted rumen fluid with or without 1.6% (fruit equivalent) ginkgo fruit extract. We conducted another series of batch culture studies to determine the dose response of fermentation. We also conducted continuous culture using the rumen simulation technique (RUSITEC) with cultivar K and carried out a pure culture study to monitor the sensitivity of 17 representative rumen bacterial species to ginkgo extract and component phenolics. Although both K and T extracts led to decreased methane and increased propionate production, changes were more apparent with K extract, and were dose-dependent. Total gas production was depressed at doses ≥3.2%, suggesting that 1.6% was the optimal supplementation level. In RUSITEC fermentation supplemented with 1.6% ginkgo K, methane decreased by 53% without affecting total gas or total VFA production, but with decreased acetate and increased propionate. Disappearance of dry matter, neutral detergent fiber, and acid detergent fiber were not affected by ginkgo, but ammonia levels were decreased. Quantitative PCR indicated that the abundance of protozoa, fungi, methanogens, and bacteria related to hydrogen and formate production decreased, but the abundance of bacteria related to propionate production increased. MiSeq analysis (Illumina Inc., San Diego, CA) confirmed these bacterial changes and identified archaeal community changes, including a decrease in Methanobrevibacter and Methanomassiliicoccaceae and an increase in Methanoplanus. Pure culture study results supported the findings for the above bacterial community changes. These results demonstrate that ginkgo fruit can modulate rumen fermentation toward methane mitigation and propionate enhancement via microbial selection. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Effects of three methane mitigation agents on parameters of kinetics of total and hydrogen gas production, ruminal fermentation and hydrogen balance using in vitro technique.

PubMed

Wang, Min; Wang, Rong; Yang, Shan; Deng, Jin Ping; Tang, Shao Xun; Tan, Zhi Liang

2016-02-01

Methane (CH4 ) can be mitigated through directly inhibiting methanogen activity and starving methanogens by hydrogen (H2 ) sink. Three types of mechanism (i.e. bromoethanesulphonate (BES), nitrate and emodin) and doses of CH4 mitigation agents were employed to investigate their pathways of CH4 inhibition. Results indicated that both BES and emodin inhibited CH4 production and altered H2 balance, which could be accompanied by decreased dry matter disappearance (DMD), fractional rate of gH2 formation, volatile fatty acid (VFA) production, ability to produce and use reducing equivalences and molecular H2 , and increased final asymptotic gH2 production, time to the peak of gH2 , discrete lag time of gH2 production and fermentation efficiency. However, emodin decreased gas volume produced by rapidly fermentable components of substrate and the rate of fermentation at early stage of incubation, while BES supplementation inhibited gas volume produced by both rapidly and slowly fermentable components of substrate and the rate of fermentation at middle or late stage of incubation. The nitrate supplementation inhibited CH4 production without affecting VFA profile, because of its dual role as H2 sink and being toxic to methanogens. Nitrate supplementation had more complicated pattern of fermentation, VFA production and profile and H2 balance in comparison to BES and emodin supplementation. © 2015 Japanese Society of Animal Science.

Novel Anaerobic Wastewater Treatment System for Energy Generation at Forward Operating Bases

DTIC Science & Technology

2016-08-01

AnMBR) technology with clinoptilolite ion exchange and GreenBox™ ammonia electrolysis. The system generates both methane and hydrogen fuels...experimental setup. ................................................ 21 Figure 10. Methane phase semi batch experimental setup, a total of three reactors were...set up for PS + solid, Bioc and ADS methane phase reactors. .................... 21 Figure 11. Dried PS solid for the control, Bioc blend for the

Disintegration in the biogas sector--technologies and effects.

PubMed

Schumacher, Britt; Wedwitschka, Harald; Hofmann, Josephine; Denysenko, Velina; Lorenz, Helge; Liebetrau, Jan

2014-09-01

Pretreatment of organic material prior to anaerobic digestion is seen as an option to increase the overall efficiency of the process. An overview of physical, chemical, and biological disintegration (DT) of substrates in the biogas sector is given. The energy demands DT were surveyed. The technologies were evaluated by reference to the Technology Readiness Assessment Guide of the U.S. Department of Energy. The evaluation focuses on ligno-cellulosic substrates like straw. Data of a survey among biogas plant operators were analyzed regarding the prevalence of disintegration technology classes in Germany. Furthermore, biochemical methane potential tests were conducted in laboratory scale to determine the specific methane yields of un-/treated barley straw (thermal pressure hydrolysis (TPH)). A methane potential of 228 ml CH4/g VS was measured for untreated barley straw; and of 251 ml CH4/g VS for TPH-straw (190 °C, 30 min). The reaction rates in BMP were calculated between 0.0976 and 0.1443 d(-1). Copyright © 2014 Elsevier Ltd. All rights reserved.

Production of Substitute Natural Gas from Coal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andrew Lucero

2009-01-31

The goal of this research program was to develop and demonstrate a novel gasification technology to produce substitute natural gas (SNG) from coal. The technology relies on a continuous sequential processing method that differs substantially from the historic methanation or hydro-gasification processing technologies. The thermo-chemistry relies on all the same reactions, but the processing sequences are different. The proposed concept is appropriate for western sub-bituminous coals, which tend to be composed of about half fixed carbon and about half volatile matter (dry ash-free basis). In the most general terms the process requires four steps (1) separating the fixed carbon frommore » the volatile matter (pyrolysis); (2) converting the volatile fraction into syngas (reforming); (3) reacting the syngas with heated carbon to make methane-rich fuel gas (methanation and hydro-gasification); and (4) generating process heat by combusting residual char (combustion). A key feature of this technology is that no oxygen plant is needed for char combustion.« less

Tapping methane hydrates for unconventional natural gas

USGS Publications Warehouse

Ruppel, Carolyn

2007-01-01

Methane hydrate is an icelike form of concentrated methane and water found in the sediments of permafrost regions and marine continental margins at depths far shallower than conventional oil and gas. Despite their relative accessibility and widespread occurrence, methane hydrates have never been tapped to meet increasing global energy demands. With rising natural gas prices, production from these unconventional gas deposits is becoming economically viable, particularly in permafrost areas already being exploited for conventional oil and gas. This article provides an overview of gas hydrate occurrence, resource assessment, exploration, production technologies, renewability, and future challenges.

Vehicle-based Methane Mapping Helps Find Natural Gas Leaks and Prioritize Leak Repairs

NASA Astrophysics Data System (ADS)

von Fischer, J. C.; Weller, Z.; Roscioli, J. R.; Lamb, B. K.; Ferrara, T.

2017-12-01

Recently, mobile methane sensing platforms have been developed to detect and locate natural gas (NG) leaks in urban distribution systems and to estimate their size. Although this technology has already been used in targeted deployment for prioritization of NG pipeline infrastructure repair and replacement, one open question regarding this technology is how effective the resulting data are for prioritizing infrastructure repair and replacement. To answer this question we explore the accuracy and precision of the natural gas leak location and emission estimates provided by methane sensors placed on Google Street View (GSV) vehicles. We find that the vast majority (75%) of methane emitting sources detected by these mobile platforms are NG leaks and that the location estimates are effective at identifying the general location of leaks. We also show that the emission rate estimates from mobile detection platforms are able to effectively rank NG leaks for prioritizing leak repair. Our findings establish that mobile sensing platforms are an efficient and effective tool for improving the safety and reducing the environmental impacts of low-pressure NG distribution systems by reducing atmospheric methane emissions.

Development of the Methane Hydrate Burning Experimental Equipment

NASA Astrophysics Data System (ADS)

Aoyama, S.

2010-12-01

There is a need to increase understanding among Japanese citizens about the importance as a potential future energy source of the great quantity of methane hydrate deposits sleeping on the sea bed around Japan. With cooperation from the Japan Oil, Gas and Metals National Corporation (JOGMEC), the National Institute of Advanced Industrial Science and Technology (AIST), and the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) we studied the possibility of using presentations where it was possible to handle actual methane hydrate, videos and active presentations such as experiments in order to increase the public interest in and understanding of methane hydrate. Furthermore, for the benefit of those people who would like to visit the exhibition but are unable to do so due to distance or other physical barriers, we looked into making the presentation materials portable and having a moving exhibition. Currently methane hydrate combustion experiments and exhibition performances are being held at the Hidaka Port New Energy Park (The Kansai Electric Power Co., Inc.) in Gobo, Wakayama with approximately 3,000 visitors monthly.

Methane oxidation in an intensively cropped tropical rice field soil under long-term application of organic and mineral fertilizers.

PubMed

Nayak, D R; Babu, Y Jagadeesh; Datta, A; Adhya, T K

2007-01-01

Methane (CH4) oxidation is the only known biological sink process for mitigating atmospheric and terrestrial emissions of CH4, a major greenhouse gas. Methane oxidation in an alluvial soil planted to rice (Oryza sativa L.) under long-term application of organic (compost with a C/N ratio of 21.71), and mineral fertilizers was measured in a field-cum-laboratory incubation study. Oxidation rates were quantified in terms of decrease in the concentration of CH4 in the headspace of incubation vessels and expressed as half-life (t(1)2) values. Methane oxidation rates significantly differed among the treatments and growth stages of the rice crop. Methane oxidation rates were high at the maximum tillering and maturity stages, whereas they were low at grain-filling stage. Methane oxidation was low (t(1)2) = 15.76 d) when provided with low concentration of CH4. On the contrary, high concentration of CH4 resulted in faster oxidation (t(1)2) = 6.67 d), suggesting the predominance of "low affinity oxidation" in rice fields. Methane oxidation was stimulated following the application of mineral fertilizers or compost implicating nutrient limitation as one of the factors affecting the process. Combined application of compost and mineral fertilizer, however, inhibited CH4 oxidation probably due to N immobilization by the added compost. The positive effect of mineral fertilizer on CH4 oxidation rate was evident only at high CH4 concentration (t(1)2 = 4.80 d), while at low CH4 concentration their was considerable suppression (t(1) = 17.60 d). Further research may reveal that long-term application of fertilizers, organic or inorganic, may not inhibit CH4 oxidation.

Linking seasonal surface water dynamics with methane emissions and export from small, forested wetlands

NASA Astrophysics Data System (ADS)

Hondula, K. L.; Palmer, M.

2017-12-01

One of the biggest uncertainties about global methane sources and sinks is attributed to uncertainties regarding wetland area and its dynamics. This is exacerbated by confusion over the role of small, shallow water bodies like Delmarva bay wetlands that could be categorized as both wetlands and ponds. These small inland water bodies are often poorly quantified due to their size, closed forest canopies, and inter- and intra-annual variability in surface water extent. We are studying wetland-rich areas on the Delmarva Peninsula in the U.S. mid-Atlantic to address this uncertainty at the scale of individual wetland ecosystems (<1000 m2). We present data linking measurements of hydrologic regime and methane gas fluxes in Delmarva bay wetlands to explore how water level, wetland storage capacity, and water residence time influence the magnitude, source area, and fate of wetland methane emissions. We measured air-water and soil-air gas fluxes using transects of chamber measurements spanning from wetland center to upland, in order to quantify the areal extent of the methane emissions source area throughout seasonal changes in surface water inundation (water level 0 to > 1m depth). We estimated the size and temporal variability of the methane emissions source area by combining these measurements with daily estimates of the extent of surface water inundation derived from water level monitoring and a high-resolution digital elevation model. This knowledge is critical for informing land use decisions (e.g. restoring wetlands specifically for climate mitigation), the jurisdiction of environmental policies in the US, and for resolving major outstanding discrepancies in our understanding of the global methane budget.

Early Fattening Lamb Could Mitigate Methane Production-an Example of Climate Smart Livestock Farming System in Indonesia

NASA Astrophysics Data System (ADS)

Purnomoadi, A.

2018-02-01

Ruminants, with a presence of rumen in their digestive tract, will produce methane during his life. Therefore, shortening the rearing period to produce a meat or milk is an alternative to reduce methane emissions. In Indonesia, in the last decades the tendency to slaughter the sheep at young age (around 5 months old) is increasing. This tendency is due to the young sheep (lamb) provide a tender meat and low in fat, as well as a faster in economical return. This study was aimed to evaluate whether shortening (and early age) fattening can reduce methane emissions. Sixteen data from two experimental sheep, each 8 heads of young sheep (aged 3 months old; initial weight 14.32+/- 1.25 kg), and 8 mature sheep (aged 12 m.o.; initial weight 20.65 +/- 1.89 kg) were used in this study. They were fed the pelleted diet formulated to give at least CP 12% and TDN 60% ad libitum. The results showed that the dry matter intake of young sheep was higher than mature sheep (1.33 vs. 1.08 kg), as well as daily gain (156 vs. 83 g/d) and the methane production (41.4vs 36.0 L/d), or methane production per kg daily gain (269 vs 434 L/kg body weight gain), although the production of methane per DMI was similar (32.0 vs 33.5 L/kg DMI). With assumption that sheep commonly weaned at 2 months old at body weight of 10 kg, and was slaughter at 22 kg of body weight, it could be calculated that shortening (and early age) fattening could reduce totally 1,984 L per head and 10 months shortened.

Mitigating Greenhouse Gas and Ammonia Emissions from Swine Manure Management: A System Analysis.

PubMed

Wang, Yue; Dong, Hongmin; Zhu, Zhiping; Gerber, Pierre J; Xin, Hongwei; Smith, Pete; Opio, Carolyn; Steinfeld, Henning; Chadwick, Dave

2017-04-18

Gaseous emissions from animal manure are considerable contributor to global ammonia (NH 3 ) and agriculture greenhouse gas (GHG) emissions. Given the demand to promote mitigation of GHGs while fostering sustainable development of the Paris Agreement, an improvement of management systems is urgently needed to help mitigate climate change and to improve atmospheric air quality. This study presents a meta-analysis and an integrated assessment of gaseous emissions and mitigation potentials for NH 3 , methane (CH 4 ), and nitrous oxide (N 2 O) (direct and indirect) losses from four typical swine manure management systems (MMSs). The resultant emission factors and mitigation efficiencies allow GHG and NH 3 emissions to be estimated, as well as mitigation potentials for different stages of swine operation. In particular, changing swine manure management from liquid systems to solid-liquid separation systems, coupled with mitigation measures, could simultaneously reduce GHG emissions by 65% and NH 3 emissions by 78%. The resultant potential reduction in GHG emissions from China's pig production alone is greater than the entire GHG emissions from agricultural sector of France, Australia, or Germany, while the reduction in NH 3 emissions is equivalent to 40% of the total NH 3 emissions from the European Union. Thus, improved swine manure management could have a significant impact on global environment issues.

Products derived from olive leaves and fruits can alter in vitro ruminal fermentation and methane production.

PubMed

Shakeri, Pirouz; Durmic, Zoey; Vadhanabhuti, Joy; Vercoe, Philip E

2017-03-01

The industrial processing of olive generates a high quantity of by-products. The objective of this study was to examine the effects of products derived from olive trees, i.e. leaves, fruits or kernels as a sole substrate (part A), and crude extract from leaves combined with a substrate (part B) on rumen microbial fermentation in an in vitro batch fermentation system. In this study, total gas production, methane production, and concentrations of volatile fatty acids (VFA) and ammonia in ruminal fluid were measured. In part A, in vitro fermentation of leaves or fruits yielded a gas and total VFA production that were comparable with control substrate, while most of them produced significantly less methane (up to 55.6%) when compared to control substrate. In part B, amongst leaf extracts, only addition of chloroform extract reduced methane production, which was also associated with a decrease (P < 0.01) in gas production. This effect was associated with a significant reduction (P < 0.01) in acetate to propionate ratio and ammonia production, but not in reduction in VFA concentrations. Olive leaf and olive leaf chloroform extract reduced ammonia production and increased the molar proportion of propionate in the rumen and can assist in developing novel feed additives for methane mitigation from the rumen. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Long-term performance and bacterial community dynamics in biocovers for mitigating methane and malodorous gases.

PubMed

Lee, Eun-Hee; Moon, Kyung-Eun; Cho, Kyung-Suk

2017-01-20

The long-term performance of lab-scale biocovers for the simulation of engineered landfill cover soils was evaluated. Methane (CH 4 ), trimethylamine (TMA), and dimethyl sulfide (DMS) were introduced into the biocovers as landfill gases for 134 days and the removal performance was evaluated. The biocover systems were capable of simultaneously removing methane, TMA, and DMS. Methane was mostly eliminated in the top layer of the systems, while TMA and DMS were removed in the bottom layer. Overall, the methane removal capacity and efficiency were 224.8±55.6g-CH 4 m -2 d -1 and 66.6±12.8%, respectively, whereas 100% removal efficiencies of both TMA and DMS were achieved. Using quantitative PCR and pyrosequencing assay, the bacterial and methanotrophic communities in the top and bottom layers were analyzed along with the removal performance of landfill gases in the biocovers. The top and bottom soil layers possessed distinct communities from the original inoculum, but their structure dynamics were different from each other. While the structures of the bacterial and methanotrophic communities showed little change in the top layer, both communities in the bottom layer were considerably shifted by adding TMA and DMA. These findings provide information that can extend the understanding of full-scale biocover performance in landfills. Copyright © 2016 Elsevier B.V. All rights reserved.

Microbial nitrogen sinks in the water column of a large coastal hypoxic area, the Gulf of Mexico "Dead Zone"

NASA Astrophysics Data System (ADS)

Rogener, M. K.; Roberts, B. J.; Rabalais, N. N.; Stewart, F. J.; Joye, S. B.

2016-02-01

Excess nitrogen in coastal environments leads to eutrophication, harmful algal blooms, habitat loss, oxygen depletion and reductions in biodiversity. As such, biological nitrogen (N) removal through the microbially-mediated process of denitrification is a critical ecosystem function that can mitigate the negative consequences of excess nitrogen loading. However, denitrification can produce nitrous oxide, a potent greenhouse gas, as a byproduct under some environmental conditions. To understand how excess nitrogen loading impacts denitrification, we measured rates of this process in the water column of the Gulf of Mexico "Dead Zone" three times over the summer of 2015. The Dead Zone is generated by excessive nitrogen loading from the Mississippi River co-occurring with strong water column stratification, which leads to a large summer-time hypoxic/anoxic area at the mouth of the river and along the coast of Louisiana. Rates of denitrification ranged from 31 to 153 nmol L-1 d-1. Dead Zone waters are also enriched in methane and aerobic methane oxidation rates ranged from 0.1 to 4.3 nmol L-1 d-1. Maximal denitrification rates were observed at stations with the lowest oxygen concentrations and highest methane oxidation rates, suggesting a potential coupling between nitrate reduction and methane oxidation which both scrubs reactive N and methane from the system, thus performing a duel ecosystem service.

Guidance for Large-scale Implementation of Alternate Wetting and Drying: A Biophysical Suitability Assessment

NASA Astrophysics Data System (ADS)

Sander, B. O.; Wassmann, R.; Nelson, A.; Palao, L.; Wollenberg, E.; Ishitani, M.

2014-12-01

The alternate wetting and drying (AWD) technology for rice production does not only save 15-30% of irrigation water, it also reduces methane emissions by up to 70%. AWD is defined by periodic drying and re-flooding of a rice field. Due to its high mitigation potential and its simplicity to execute this practice AWD has gained a lot of attention in recent years. The Climate and Clean Air Coalition (CCAC) has put AWD high on its agenda and funds a project to guide implementation of this technology in Vietnam, Bangladesh and Colombia. One crucial activity is a biophysical suitability assessment for AWD in the three countries. For this, we analyzed rainfall and soil data as well as potential evapotranspiration to assess if the water balance allows practicing AWD or if precipitation is too high for rice fields to fall dry. In my talk I will outline key factors for a successful large-scale implementation of AWD with a focus on the biophysical suitability assessment. The seasonal suitability maps that we generated highlight priority areas for AWD implementation and guide policy makers to informed decisions about meaningful investments in infrastructure and extension work.

The Value of Linking Mitigation and Adaptation: A Case Study of Bangladesh

NASA Astrophysics Data System (ADS)

Ayers, Jessica M.; Huq, Saleemul

2009-05-01

There are two principal strategies for managing climate change risks: mitigation and adaptation. Until recently, mitigation and adaptation have been considered separately in both climate change science and policy. Mitigation has been treated as an issue for developed countries, which hold the greatest responsibility for climate change, while adaptation is seen as a priority for the South, where mitigative capacity is low and vulnerability is high. This conceptual divide has hindered progress against the achievement of the fundamental sustainable development challenges of climate change. Recent attention to exploring the synergies between mitigation and adaptation suggests that an integrated approach could go some way to bridging the gap between the development and adaptation priorities of the South and the need to achieve global engagement in mitigation. These issues are explored through a case study analysis of climate change policy and practice in Bangladesh. Using the example of waste-to-compost projects, a mitigation-adaptation-development nexus is demonstrated, as projects contribute to mitigation through reducing methane emissions; adaptation through soil improvement in drought-prone areas; and sustainable development, because poverty is exacerbated when climate change reduces the flows of ecosystem services. Further, linking adaptation to mitigation makes mitigation action more relevant to policymakers in Bangladesh, increasing engagement in the international climate change agenda in preparation for a post-Kyoto global strategy. This case study strengthens the argument that while combining mitigation and adaptation is not a magic bullet for climate policy, synergies, particularly at the project level, can contribute to the sustainable development goals of climate change and are worth exploring.

The value of linking mitigation and adaptation: a case study of Bangladesh.

PubMed

Ayers, Jessica M; Huq, Saleemul

2009-05-01

There are two principal strategies for managing climate change risks: mitigation and adaptation. Until recently, mitigation and adaptation have been considered separately in both climate change science and policy. Mitigation has been treated as an issue for developed countries, which hold the greatest responsibility for climate change, while adaptation is seen as a priority for the South, where mitigative capacity is low and vulnerability is high. This conceptual divide has hindered progress against the achievement of the fundamental sustainable development challenges of climate change. Recent attention to exploring the synergies between mitigation and adaptation suggests that an integrated approach could go some way to bridging the gap between the development and adaptation priorities of the South and the need to achieve global engagement in mitigation. These issues are explored through a case study analysis of climate change policy and practice in Bangladesh. Using the example of waste-to-compost projects, a mitigation-adaptation-development nexus is demonstrated, as projects contribute to mitigation through reducing methane emissions; adaptation through soil improvement in drought-prone areas; and sustainable development, because poverty is exacerbated when climate change reduces the flows of ecosystem services. Further, linking adaptation to mitigation makes mitigation action more relevant to policymakers in Bangladesh, increasing engagement in the international climate change agenda in preparation for a post-Kyoto global strategy. This case study strengthens the argument that while combining mitigation and adaptation is not a magic bullet for climate policy, synergies, particularly at the project level, can contribute to the sustainable development goals of climate change and are worth exploring.

LanzaTech- Capturing Carbon. Fueling Growth.

ScienceCinema

NONE

2018-01-16

LanzaTech will design a gas fermentation system that will significantly improve the rate at which methane gas is delivered to a biocatalyst. Current gas fermentation processes are not cost effective compared to other gas-to-liquid technologies because they are too slow for large-scale production. If successful, LanzaTech's system will process large amounts of methane at a high rate, reducing the energy inputs and costs associated with methane conversion.

Renewable Energy Production from DoD Installation Solid Wastes by Anaerobic Digestion

DTIC Science & Technology

2016-06-01

and purification of methane -rich biogas was conducted at the US Air Force Academy. Cost and performance of the technology with respect to renewable...SUBJECT TERMS Food waste, FOG, solid waste, anaerobic digestion, methane , biogas, biomethane, biogas purification, vehicle fuel, renewable energy...The project demonstrated the ability to digest these wastes in a controlled and predictable manner to maximize the generation of biogas, a methane

Phytoremediation of Atmospheric Methane

DTIC Science & Technology

2013-04-15

REPORT Phytoremediation of Atmospheric Methane 14. ABSTRACT 16. SECURITY CLASSIFICATION OF: We have transformed a plant, Arabidopsis thaliana, with the...298 (Rev 8/98) Prescribed by ANSI Std. Z39.18 - 31-Mar-2012 Phytoremediation of Atmospheric Methane Report Title ABSTRACT We have transformed a...DD882) Scientific Progress See attachment Technology Transfer 1    Final Report for DARPA project W911NF1010027  Phytoremediation  of Atmospheric

The Methane to Markets Coal Mine Methane Subcommittee meeting

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

2008-07-01

The presentations (overheads/viewgraphs) include: a report from the Administrative Support Group; strategy updates from Australia, India, Italy, Mexico, Nigeria, Poland and the USA; coal mine methane update and IEA's strategy and activities; the power of VAM - technology application update; the emissions trading market; the voluntary emissions reduction market - creating profitable CMM projects in the USA; an Italian perspective towards a zero emission strategies; and the wrap-up and summary.

JPRS Report. Science & Technology: Japan

DTIC Science & Technology

1987-07-16

methane. So, it has been proved that seawater containing methane and sulfur, which oozed out at this point from underground, grew bacteria, a food ...activity was measured by dispersing glass powder at the seabed and the speed of extinction due to food poisoning was also measured by leaving dead...solar light is very small due to the scarcity of food . However, a special ecosystem nourished with bacteria, which eat methane and inorganic compounds

Testing of a Methane Cryogenic Heat Pipe with a Liquid Trap Turn-Off Feature for use on Space Interferometer Mission (SIM)

NASA Technical Reports Server (NTRS)

Cepeda-Rizo, Juan; Krylo, Robert; Fisher, Melanie; Bugby, David C.

2011-01-01

Camera cooling for SIM presents three thermal control challenges; stable operation at 163K (110 C), decontamination heating to +20 C, and a long span from the cameras to the radiator. A novel cryogenic cooling system based on a methane heat pipe meets these challenges. The SIM thermal team, with the help of heat pipe vendor ATK, designed and tested a complete, low temperature, cooling system. The system accommodates the two SIM cameras with a double-ended conduction bar, a single methane heat pipe, independent turn-off devices, and a flight-like radiator. The turn ]off devices consist of a liquid trap, for removing the methane from the pipe, and an electrical heater to raise the methane temperature above the critical point thus preventing two-phase operation. This is the first time a cryogenic heat pipe has been tested at JPL and is also the first heat pipe to incorporate the turn-off features. Operation at 163K with a methane heat pipe is an important new thermal control capability for the lab. In addition, the two turn-off technologies enhance the "bag of tricks" available to the JPL thermal community. The successful test program brings this heat pipe to a high level of technology readiness.

Research on the theory and application of adsorbed natural gas used in new energy vehicles: A review

NASA Astrophysics Data System (ADS)

Nie, Zhengwei; Lin, Yuyi; Jin, Xiaoyi

2016-09-01

Natural gas, whose primary constituent is methane, has been considered a convincing alternative for the growth of the energy supply worldwide. Adsorbed natural gas (ANG), the most promising methane storage method, has been an active field of study in the past two decades. ANG constitutes a safe and low-cost way to store methane for natural gas vehicles at an acceptable energy density while working at substantially low pressures (3.5-4.0 MPa), allowing for conformable store tank. This work serves to review the state-of-the-art development reported in the scientific literature on adsorbents, adsorption theories, ANG conformable tanks, and related technologies on ANG vehicles. Patent literature has also been searched and discussed. The review aims at illustrating both achievements and problems of the ANG technologies- based vehicles, as well as forecasting the development trends and critical issues to be resolved of these technologies.

Roles of Sodium Dodecyl Sulfate on Tetrahydrofuran-Assisted Methane Hydrate Formation.

PubMed

Siangsai, Atsadawuth; Inkong, Katipot; Kulprathipanja, Santi; Kitiyanan, Boonyarach; Rangsunvigit, Pramoch

2018-06-01

Sodium dodecyl sulfate (SDS) markedly improved tetrahydrofuran (THF) - assisted methane hydrate formation. Firstly, methane hydrate formation with different THF amount, 1, 3, and 5.56 mol%, was studied. SDS with 1, 4, and 8 mM was then investigated for its roles on the methane hydrate formation with and without THF. The experiments were conducted in a quiescent condition in a fixed volume crystallizer at 8 MPa and 4°C. The results showed that almost all studied THF and SDS concentrations enhanced the methane hydrate formation kinetics and methane consumption compared to that without the promoters, except 1 mol% THF. Although, with 1 mol% THF, there were no hydrates formed for 48 hours, the addition of just 1 mM SDS surprisingly promoted the hydrate formation with a significant increased in the kinetics. This prompts the use of methane hydrate technology for natural gas storage application with minimal promoters.

Teachers' Initial and Sustained Use of an Instructional Assistive Technology Tool: Exploring the Mitigating Factors

ERIC Educational Resources Information Center

Bouck, Emily C.; Flanagan, Sara; Heutsche, Anne; Okolo, Cynthia M.; Englert, Carol Sue

2011-01-01

This qualitative research project explored factors that mitigated teachers implementing an instructional assistive technology and factors that mitigated its sustained use. Specifically, it explored these issues in relation to a social studies based instructional assistive technology (Virtual History Museum [VHM]), which was originally implemented…

Bioelectrochemical enhancement of methane production from highly concentrated food waste in a combined anaerobic digester and microbial electrolysis cell.

PubMed

Park, Jungyu; Lee, Beom; Tian, Donjie; Jun, Hangbae

2018-01-01

A microbial electrolysis cell (MEC) is a promising technology for enhancing biogas production from an anaerobic digestion (AD) reactor. In this study, the effects of the MEC on the rate of methane production from food waste were examined by comparing an AD reactor with an AD reactor combined with a MEC (AD+MEC). The use of the MEC accelerated methane production and stabilization via rapid organic oxidation and rapid methanogenesis. Over the total experimental period, the methane production rate and stabilization time of the AD+MEC reactor were approximately 1.7 and 4.0 times faster than those of the AD reactor. Interestingly however, at the final steady state, the methane yields of both the reactors were similar to the theoretical maximum methane yield. Based on these results, the MEC did not increase the methane yield over the theoretical value, but accelerated methane production and stabilization by bioelectrochemical reactions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Rumen protozoa and methanogenesis: not a simple cause-effect relationship.

PubMed

Morgavi, Diego P; Martin, Cécile; Jouany, Jean-Pierre; Ranilla, Maria José

2012-02-01

Understanding the interactions between hydrogen producers and consumers in the rumen ecosystem is important for ruminant production and methane mitigation. The present study explored the relationships between rumen protozoa, methanogens and fermentation characteristics. A total of six donor sheep harbouring (F, faunated) or not (D, defaunated) protozoa in their rumens (D animals were kept without protozoa for a period of a few months (D - ) or for more than 2 years (D+)) were used in in vitro and in vivo experiments. In vitro the absence of protozoa decreased NH3 and butyrate production and had no effect on methane. In contrast, the liquid-associated bacterial and methanogens fraction of D+ inocula produced more methane than D -  and F inoculum (P < 0·05). In vivo fermentation parameters of donor animals showed the same trend on NH3 and butyrate and showed that D+ animals were high methane emitters, while D -  were the lowest ( - 35 %). The concentration of dissolved dihydrogen measured after feeding followed the opposite trend. Methane emissions did not correlate with the relative abundance of methanogens in the rumen measured by quantitative PCR, but there was a trend for higher methanogens concentration in the solid-associated population of D+ animals compared with D -  animals. In contrast, PCR-denaturing gradient gel electrophoresis profiles of methanogens' methyl coenzyme-M reductase A gene showed a clear clustering in liquid-associated fractions for all three groups of donors but fewer differences in solid-associated fractions. These results show that the absence of protozoa may affect differently the methanogen community and methane emissions in wethers.

Low NO{sub x} turbine power generation utilizing low Btu GOB gas. Final report, June--August 1995

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ortiz, I.; Anthony, R.V.; Gabrielson, J.

1995-08-01

Methane, a potent greenhouse gas, is second only to carbon dioxide as a contributor to potential global warming. Methane liberated by coal mines represents one of the most promising under exploited areas for profitably reducing these methane emissions. Furthermore, there is a need for apparatus and processes that reduce the nitrogen oxide (NO{sub x}) emissions from gas turbines in power generation. Consequently, this project aims to demonstrate a technology which utilizes low grade fuel (CMM) in a combustion air stream to reduce NO{sub x} emissions in the operation of a gas turbine. This technology is superior to other existing technologiesmore » because it can directly use the varying methane content gases from various streams of the mining operation. The simplicity of the process makes it useful for both new gas turbines and retrofitting existing gas turbines. This report evaluates the feasibility of using gob gas from the 11,000 acre abandoned Gateway Mine near Waynesburg, Pennsylvania as a fuel source for power generation applying low NO{sub x} gas turbine technology at a site which is currently capable of producing low grade GOB gas ({approx_equal} 600 BTU) from abandoned GOB areas.« less

Cryogenic Technology Development for Exploration Missions

NASA Technical Reports Server (NTRS)

Chato, David J.

2007-01-01

This paper reports the status and findings of different cryogenic technology research projects in support of the President s Vision for Space Exploration. The exploration systems architecture study is reviewed for cryogenic fluid management needs. It is shown that the exploration architecture is reliant on the cryogenic propellants of liquid hydrogen, liquid oxygen and liquid methane. Needs identified include: the key technologies of liquid acquisition devices, passive thermal and pressure control, low gravity mass gauging, prototype pressure vessel demonstration, active thermal control; as well as feed system testing, and Cryogenic Fluid Management integrated system demonstration. Then five NASA technology projects are reviewed to show how these needs are being addressed by technology research. Projects reviewed include: In-Space Cryogenic Propellant Depot; Experimentation for the Maturation of Deep Space Cryogenic Refueling Technology; Cryogenic Propellant Operations Demonstrator; Zero Boil-Off Technology Experiment; and Propulsion and Cryogenic Advanced Development. Advances are found in the areas of liquid acquisition of liquid oxygen, mass gauging of liquid oxygen via radio frequency techniques, computational modeling of thermal and pressure control, broad area cooling thermal control strategies, flight experiments for resolving low gravity issues of cryogenic fluid management. Promising results are also seen for Joule-Thomson pressure control devices in liquid oxygen and liquid methane and liquid acquisition of methane, although these findings are still preliminary.

Current experiences in applied underground coal gasification

NASA Astrophysics Data System (ADS)

Peters, Justyn

2010-05-01

The world is experiencing greater stress on its ability to mine and exploit energy resources such as coal, through traditional mining methods. The resources available by extraction from traditional mining methods will have a finite time and quantity. In addition, the high quality coals available are becoming more difficult to find substantially increasing exploration costs. Subsequently, new methods of extraction are being considered to improve the ability to unlock the energy from deep coals and improve the efficiency of the exploitation of the resources while also considering the mitigation of global warming. Underground Coal Gasification (UCG) is a leading commercial technology that is able to maximize the exploitation of the deep coal through extraction of the coal as a syngas (CO and H2) in situ. The syngas is then brought to the surface and efficiently utilized in any of combined cycle power generation, liquid hydrocarbon transport fuel production, fertilizer production or polymer production. Commercial UCG has been successfully operating for more than 50 years at the Yerostigaz facility in Angren, Uzbekistan. Yerostigaz is the only remaining UCG site in the former Soviet Union. Linc Energy currently owns 91.6% of this facility. UCG produces a high quality synthetic gas (syngas), containing carbon monoxide, hydrogen and methane. UCG produced syngas can be economically used for a variety of purposes, including: the production of liquid fuels when combined with Gas to Liquids (GTL) technology power generation in gas turbine combined cycle power stations a feedstock for different petrochemical processes, for example producing chemicals or other gases such as hydrogen, methane, ammonia, methanol and dimethyl ether Linc Energy has proven the combined use of UCG to Gas to Liquids (GTL) technologies. UCG to GTL technologies have the ability to provide energy alternatives to address increasing global demand for energy products. With these technologies, Linc Energy is set to become the leading producer of cleaner liquid fuels and other associated products. UCG has now been developed to a point where the commercialisation of the process is no longer questioned, the economics of the process are compelling, and is now seen as a method that resolves energy security for countries that have access to deep coal previously thought to have no economic value.

Lambs Fed Fresh Winter Forage Rape (Brassica napus L.) Emit Less Methane than Those Fed Perennial Ryegrass (Lolium perenne L.), and Possible Mechanisms behind the Difference

PubMed Central

Sun, Xuezhao; Henderson, Gemma; Cox, Faith; Molano, German; Harrison, Scott J.; Luo, Dongwen; Janssen, Peter H.; Pacheco, David

2015-01-01

The objectives of this study were to examine long-term effects of feeding forage rape (Brassica napus L.) on methane yields (g methane per kg of feed dry matter intake), and to propose mechanisms that may be responsible for lower emissions from lambs fed forage rape compared to perennial ryegrass (Lolium perenne L.). The lambs were fed fresh winter forage rape or ryegrass as their sole diet for 15 weeks. Methane yields were measured using open circuit respiration chambers, and were 22-30% smaller from forage rape than from ryegrass (averages of 13.6 g versus 19.5 g after 7 weeks, and 17.8 g versus 22.9 g after 15 weeks). The difference therefore persisted consistently for at least 3 months. The smaller methane yields from forage rape were not related to nitrate or sulfate in the feed, which might act as alternative electron acceptors, or to the levels of the potential inhibitors glucosinolates and S-methyl L-cysteine sulfoxide. Ruminal microbial communities in forage rape-fed lambs were different from those in ryegrass-fed lambs, with greater proportions of potentially propionate-forming bacteria, and were consistent with less hydrogen and hence less methane being produced during fermentation. The molar proportions of ruminal acetate were smaller and those of propionate were greater in forage rape-fed lambs, consistent with the larger propionate-forming populations and less hydrogen production. Forage rape contained more readily fermentable carbohydrates and less structural carbohydrates than ryegrass, and was more rapidly degraded in the rumen, which might favour this fermentation profile. The ruminal pH was lower in forage rape-fed lambs, which might inhibit methanogenic activity, shifting the rumen fermentation to more propionate and less hydrogen and methane. The significance of these two mechanisms remains to be investigated. The results suggest that forage rape is a potential methane mitigation tool in pastoral-based sheep production systems. PMID:25803688

2004 Methane and Nitrous Oxide Emissions from Manure Management in South Africa

PubMed Central

Moeletsi, Mokhele Edmond; Tongwane, Mphethe Isaac

2015-01-01

Simple Summary Livestock manure management is one of the main sources of greenhouse gas (GHG) emissions in South Africa producing mainly methane and nitrous oxide. The emissions from this sub-category are dependent on how manure is stored. Liquid-stored manure predominantly produces methane while dry-based manure enhances mainly production of nitrous oxide. Intergovernmental Panel on Climate Change (IPCC) guidelines were utilized at different tier levels in estimating GHG emissions from manure management. The results show that methane emissions are relatively higher than nitrous oxide emissions with 3104 Gg and 2272 Gg respectively in carbon dioxide global warming equivalent. Abstract Manure management in livestock makes a significant contribution towards greenhouse gas emissions in the Agriculture; Forestry and Other Land Use category in South Africa. Methane and nitrous oxide emissions are prevalent in contrasting manure management systems; promoting anaerobic and aerobic conditions respectively. In this paper; both Tier 1 and modified Tier 2 approaches of the IPCC guidelines are utilized to estimate the emissions from South African livestock manure management. Activity data (animal population, animal weights, manure management systems, etc.) were sourced from various resources for estimation of both emissions factors and emissions of methane and nitrous oxide. The results show relatively high methane emissions factors from manure management for mature female dairy cattle (40.98 kg/year/animal), sows (25.23 kg/year/animal) and boars (25.23 kg/year/animal). Hence, contributions for pig farming and dairy cattle are the highest at 54.50 Gg and 32.01 Gg respectively, with total emissions of 134.97 Gg (3104 Gg CO2 Equivalent). Total nitrous oxide emissions are estimated at 7.10 Gg (2272 Gg CO2 Equivalent) and the three main contributors are commercial beef cattle; poultry and small-scale beef farming at 1.80 Gg; 1.72 Gg and 1.69 Gg respectively. Mitigation options from manure management must be taken with care due to divergent conducive requirements of methane and nitrous oxide emissions requirements. PMID:26479229

A Metagenomics-Based Metabolic Model of Nitrate-Dependent Anaerobic Oxidation of Methane by Methanoperedens-Like Archaea

PubMed Central

Arshad, Arslan; Speth, Daan R.; de Graaf, Rob M.; Op den Camp, Huub J. M.; Jetten, Mike S. M.; Welte, Cornelia U.

2015-01-01

Methane oxidation is an important process to mitigate the emission of the greenhouse gas methane and further exacerbating of climate forcing. Both aerobic and anaerobic microorganisms have been reported to catalyze methane oxidation with only a few possible electron acceptors. Recently, new microorganisms were identified that could couple the oxidation of methane to nitrate or nitrite reduction. Here we investigated such an enrichment culture at the (meta) genomic level to establish a metabolic model of nitrate-driven anaerobic oxidation of methane (nitrate-AOM). Nitrate-AOM is catalyzed by an archaeon closely related to (reverse) methanogens that belongs to the ANME-2d clade, tentatively named Methanoperedens nitroreducens. Methane may be activated by methyl-CoM reductase and subsequently undergo full oxidation to carbon dioxide via reverse methanogenesis. All enzymes of this pathway were present and expressed in the investigated culture. The genome of the archaeal enrichment culture encoded a variety of enzymes involved in an electron transport chain similar to those found in Methanosarcina species with additional features not previously found in methane-converting archaea. Nitrate reduction to nitrite seems to be located in the pseudoperiplasm and may be catalyzed by an unusual Nar-like protein complex. A small part of the resulting nitrite is reduced to ammonium which may be catalyzed by a Nrf-type nitrite reductase. One of the key questions is how electrons from cytoplasmically located reverse methanogenesis reach the nitrate reductase in the pseudoperiplasm. Electron transport in M. nitroreducens probably involves cofactor F420 in the cytoplasm, quinones in the cytoplasmic membrane and cytochrome c in the pseudoperiplasm. The membrane-bound electron transport chain includes F420H2 dehydrogenase and an unusual Rieske/cytochrome b complex. Based on genome and transcriptome studies a tentative model of how central energy metabolism of nitrate-AOM could work is presented and discussed. PMID:26733968

Fugitive methane assessment with mobile and fence line sensors

EPA Science Inventory

There is no published abstract for this short panel talk. The panel presentation titled “Fugitive methane assessment with mobile and fence line sensors” provides a basic introduction to the topic of next generation sensor technologies for identifying and fixing emiss...

Atmospheric impacts of a natural gas development within the urban context of Morgantown, West Virginia.

PubMed

Williams, Philip J; Reeder, Matthew; Pekney, Natalie J; Risk, David; Osborne, John; McCawley, Michael

2018-10-15

The Marcellus Shale Energy and Environment Laboratory (MSEEL) in West Virginia provides a unique opportunity in the field of unconventional energy research. By studying near-surface atmospheric chemistry over several phases of a hydraulic fracturing event, the project will help evaluate the impact of current practices, as well as new techniques and mitigation technologies. A total of 10 mobile surveys covering a distance of approximately 1500 km were conducted through Morgantown. Our surveying technique involved using a vehicle-mounted Los Gatos Research gas analyzer to provide geo-located measurements of methane (CH 4 ) and carbon dioxide (CO 2 ). The ratios of super-ambient concentrations of CO 2 and CH 4 were used to separate well-pad emissions from the natural background concentrations over the various stages of well-pad development, as well as for comparisons to other urban sources of CH 4 . We found that regional background methane concentrations were elevated in all surveys, with a mean concentration of 2.699 ± 0.006 ppmv, which simply reflected the complexity of this riverine urban location. Emissions at the site were the greatest during the flow-back phase, with an estimated CH 4 volume output of 20.62 ± 7.07 g/s, which was significantly higher than other identified urban emitters. Our study was able to successfully identify and quantify MSEEL emissions within this complex urban environment. Copyright © 2018 Elsevier B.V. All rights reserved.

Headspace Analysis of Ammonium Nitrate

DTIC Science & Technology

2017-01-25

to an Agilent 7890 gas chromatograph (GC) (Agilent Technologies, Santa Clara, CA). Methane CI was used to optimize instrument parameters, which...order of 0.1 mTorr, as were CF2Cl2, CF3Cl, methane , and isobutane. Figure 2. Analyte sorbent tube mounted and interfaced with a modified GC...observed at no more than 22% abundance of m/z 17. When larger gases such as methane were mixed in significant proportion with 500 ppm carbon

Methane from the Tropospheric Emission Spectrometer (TES)

NASA Technical Reports Server (NTRS)

Payne, Vivienne; Worden, John; Kulawik, Susan; Frankenberg, Christian; Bowman, Kevin; Wecht, Kevin

2012-01-01

TES V5 CH4 captures latitudinal gradients, regional variability and interannual variation in the free troposphere. V5 joint retrievals offer improved sensitivity to lower troposphere. Time series extends from 2004 to present. V5 reprocessing in progress. Upper tropospheric bias. Mitigated by N2O correction. Appears largely spatially uniform, so can be corrected. How to relate free-tropospheric values to surface emissions.

Contribution of condensed tannins and mimosine to the methane mitigation caused by feeding Leucaena leucocephala.

PubMed

Soltan, Yosra A; Morsy, Amr S; Sallam, Sobhy M A; Lucas, Ronaldo C; Louvandini, Helder; Kreuzer, Michael; Abdalla, Adibe L

2013-06-01

Leucaena (Leucaena leucocephala), a leguminous shrub promising to cope with feed scarcity in the tropics, may help in mitigating ruminal methane (CH4) emission in the tropics as well. Two experiments were conducted to evaluate the effect of Leucaena and major secondary compounds of this plant in ruminants. At first, effects of Leucaena tannins and mimosine on ruminal CH4 and nutrient degradability were tested in vitro. Incubations were made with Leucaena without or with polyethylene glycol (PEG) to exclude the tannins effects, as well as with Bermuda grass (Tifton) and lucerne hays, both either untreated or supplemented with mimosine at the same concentration that has been provided by the tested Leucaena (6.52 mg/g DM). Furthermore, in an in vivo experiment a control diet (per kg DM 700 g Tifton hay) and Leucaena diets (per kg DM 350 g Tifton hay and 350 g Leucaena), either with or without 20 g PEG/d per head, were evaluated in six Santa Inês sheep following a double Latin square design. In vitro, Leucaena resulted in the lowest (p < 0.05) gas and CH4 production and the highest (p < 0.05) partitioning factor, a measure for microbial efficiency, whereas the amount of truly degraded organic matter (TDOM) was lowest (p < 0.05) with Tifton among the experimental forage plants. Mimosine addition to lucerne and Tifton as well as PEG addition to Leucaena had no effect on ruminal CH4 and TDOM. In vivo Leucaena, compared to the Tifton diet, enhanced (p < 0.05) intake, faecal nitrogen excretion, body nitrogen retention and the excretion of urinary purine derivatives as an indicator for microbial protein synthesis and availability. This was independent of PEG addition. Leucaena also decreased (p < 0.001) CH4 emission per unit of digested organic matter by 14.1% and 10.8%, without and with PEG, respectively. No significant diet differences were observed in total-tract nutrient digestibility. The study demonstrated efficiency of Leucaena to mitigate in vivo methane emission of sheep, but did not reveal which constituent of Leucaena was primarily responsible for that since no clear efficiency of either tannins or mimosine could be demonstrated.

Biochars mitigate greenhouse gas emissions and bioaccumulation of potentially toxic elements and arsenic speciation in Phaseolus vulgaris L.

PubMed

Ibrahim, Muhammad; Li, Gang; Khan, Sardar; Chi, Qiaoqiao; Xu, Yaoyang; Zhu, Yongguan

2017-08-01

Anthropogenic and natural activities can lead to increased greenhouse gas emissions and discharge of potentially toxic elements (PTEs) into soil environment. Biochar amendment to soils is a cost-effective technology and sustainable approach used to mitigate greenhouse gas emissions, improve phytoremediation, and minimize the health risks associated with consumption of PTE-contaminated vegetables. Greenhouse pot experiments were conducted to investigate the effects of peanut shell biochar (PNB) and sewage sludge biochar (SSB) on greenhouse gas (GHG) emissions, plant growth, PTE bioaccumulation, and arsenic (As) speciation in bean plants. Results indicated that amendments of PNB and SSB increased plant biomass production by increasing soil fertility and reducing bioavailability of PTEs. Addition of biochars also increased soil pH, total nitrogen (TN), total carbon (TC), dissolved organic carbon (DOC), and ammonium-nitrogen (NH 4 -N) but decreased available concentrations of PTEs such as cadmium (Cd), lead (Pb), and As. The concentration of nitrate-nitrogen (NO 3 - -N) was also decreased in biochar-amended soils. In addition, PNB and SSB amendments significantly (P < 0.01) reduced the bioaccumulation of chromium (Cr), As, Cd, Pb, and nickel (Ni) in stalks, leaves, and fruits of Phaseolus vulgaris L. Similarly, PNB and SSB amendments significantly (P ≤ 0.05) reduced inorganic As species like arsenite (As (III)) and arsenate (As (V)). Greenhouse gases such as carbon dioxide (CO 2 ) and methane (CH 4 ) emissions were significantly (P < 0.01) reduced but nitrous oxide (N 2 O) emissions first increased and then decreased amended with both biochars. Current findings demonstrate that SSB and PNB are two beneficial soil amendments simultaneous mitigating greenhouse gas emissions and PTE bioaccumulation as well as arsenic speciation in P. vulgaris L.

Utilization of farm animal genetic resources in a changing agro-ecological environment in the Nordic countries.

PubMed

Kantanen, Juha; Løvendahl, Peter; Strandberg, Erling; Eythorsdottir, Emma; Li, Meng-Hua; Kettunen-Præbel, Anne; Berg, Peer; Meuwissen, Theo

2015-01-01

Livestock production is the most important component of northern European agriculture and contributes to and will be affected by climate change. Nevertheless, the role of farm animal genetic resources in the adaptation to new agro-ecological conditions and mitigation of animal production's effects on climate change has been inadequately discussed despite there being several important associations between animal genetic resources and climate change issues. The sustainability of animal production systems and future food security require access to a wide diversity of animal genetic resources. There are several genetic questions that should be considered in strategies promoting adaptation to climate change and mitigation of environmental effects of livestock production. For example, it may become important to choose among breeds and even among farm animal species according to their suitability to a future with altered production systems. Some animals with useful phenotypes and genotypes may be more useful than others in the changing environment. Robust animal breeds with the potential to adapt to new agro-ecological conditions and tolerate new diseases will be needed. The key issue in mitigation of harmful greenhouse gas effects induced by livestock production is the reduction of methane (CH4) emissions from ruminants. There are differences in CH4 emissions among breeds and among individual animals within breeds that suggest a potential for improvement in the trait through genetic selection. Characterization of breeds and individuals with modern genomic tools should be applied to identify breeds that have genetically adapted to marginal conditions and to get critical information for breeding and conservation programs for farm animal genetic resources. We conclude that phenotyping and genomic technologies and adoption of new breeding approaches, such as genomic selection introgression, will promote breeding for useful characters in livestock species.

Utilization of farm animal genetic resources in a changing agro-ecological environment in the Nordic countries

PubMed Central

Kantanen, Juha; Løvendahl, Peter; Strandberg, Erling; Eythorsdottir, Emma; Li, Meng-Hua; Kettunen-Præbel, Anne; Berg, Peer; Meuwissen, Theo

2015-01-01

Livestock production is the most important component of northern European agriculture and contributes to and will be affected by climate change. Nevertheless, the role of farm animal genetic resources in the adaptation to new agro-ecological conditions and mitigation of animal production’s effects on climate change has been inadequately discussed despite there being several important associations between animal genetic resources and climate change issues. The sustainability of animal production systems and future food security require access to a wide diversity of animal genetic resources. There are several genetic questions that should be considered in strategies promoting adaptation to climate change and mitigation of environmental effects of livestock production. For example, it may become important to choose among breeds and even among farm animal species according to their suitability to a future with altered production systems. Some animals with useful phenotypes and genotypes may be more useful than others in the changing environment. Robust animal breeds with the potential to adapt to new agro-ecological conditions and tolerate new diseases will be needed. The key issue in mitigation of harmful greenhouse gas effects induced by livestock production is the reduction of methane (CH4) emissions from ruminants. There are differences in CH4 emissions among breeds and among individual animals within breeds that suggest a potential for improvement in the trait through genetic selection. Characterization of breeds and individuals with modern genomic tools should be applied to identify breeds that have genetically adapted to marginal conditions and to get critical information for breeding and conservation programs for farm animal genetic resources. We conclude that phenotyping and genomic technologies and adoption of new breeding approaches, such as genomic selection introgression, will promote breeding for useful characters in livestock species. PMID:25767477

Occurrence of methane in groundwater of south-central New York State, 2012-systematic evaluation of a glaciated region by hydrogeologic setting

USGS Publications Warehouse

Heisig, Paul M.; Scott, Tia-Marie

2013-01-01

A survey of methane in groundwater was undertaken to document methane occurrence on the basis hydrogeologic setting within a glaciated 1,810-square-mile area of south-central New York along the Pennsylvania border. Sixty-six wells were sampled during the summer of 2012. All wells were at least 1 mile from any known gas well (active, exploratory, or abandoned). Results indicate strong positive and negative associations between hydrogeologic settings and methane occurrence. The hydrogeologic setting classes are based on topographic position (valley and upland), confinement or non-confinement of groundwater by glacial deposits, well completion in fractured bedrock or sand and gravel, and hydrogeologic subcategories. Only domestic wells and similar purposed supply wells with well-construction and log information were selected for classification. Field water-quality characteristics (pH, specific conductance, dissolved oxygen, and temperature) were measured at each well, and samples were collected and analyzed for dissolved gases, including methane and short-chain hydrocarbons. Carbon and hydrogen isotopic ratios of methane were measured in 21 samples that had at least 0.3 milligram per liter (mg/L) of methane. Results of sampling indicate that occurrence of methane in groundwater of the region is common—greater than or equal to 0.001 mg/L in 78 percent of the groundwater samples. Concentrations of methane ranged over five orders of magnitude. Methane concentrations at which monitoring or mitigation are indicated (greater than or equal to 10 mg/L) were measured in 15 percent of the samples. Methane concentrations greater than 0.1 mg/L were associated with specific hydrogeologic settings. Wells completed in bedrock within valleys and under confined groundwater conditions were most closely associated with the highest methane concentrations. Fifty-seven percent of valley wells had greater than or equal to 0.1 mg/L of methane, whereas only 10 percent of upland wells equaled or exceeded that concentration. Isotopic signatures differed between these groups as well. Methane in valley wells was predominantly thermogenic in origin, likely as a result of close vertical proximity to underlying methane-bearing saline groundwater and brine and possibly as a result of enhanced bedrock fracture permeability beneath valleys that provides an avenue for upward gas migration. Isotopic signatures of methane from four upland well samples indicated a microbial origin (carbon-dioxide reduction) with one sample possibly altered by microbial methane oxidation. Water samples from wells in a valley setting that indicate a mix of thermogenic and microbial methane reflect the close proximity of regional groundwater flow and underlying saline water and brine in valley areas. The microbial methane is likely produced by bacteria that utilize carbon dioxide or formational organic matter in highly reducing environments within the subregional groundwater flow system. This characterization of groundwater methane shows the importance of subsurface information (hydrogeology, well construction) in understanding methane occurrence and provides an initial conceptual framework that can be utilized in investigation of stray gas in south-central New York.

Evaluation of Sorbents for Acetylene Separation in Atmosphere Revitalization Loop Closure

NASA Technical Reports Server (NTRS)

Abney, Morgan B.; Miller, Lee A.; Barton, Katherine

2012-01-01

State-of-the-art carbon dioxide reduction technology uses a Sabatier reactor to recover water from metabolic carbon dioxide. In order to maximize oxygen loop closure, a byproduct of the system, methane, must be reduced to recover hydrogen. NASA is currently exploring a microwave plasma methane pyrolysis system for this purpose. The resulting product stream of this technology includes unreacted methane, product hydrogen, and acetylene. The hydrogen and the small amount of unreacted methane resulting from the pyrolysis process can be returned to the Sabatier reactor thereby substantially improving the overall efficiency of the system. However, the acetylene is a waste product that must be removed from the pyrolysis product. Two materials have been identified as potential sorbents for acetylene removal: zeolite 4A, a commonly available commercial sorbent, and HKUST-1, a newly developed microporous metal. This paper provides an explanation of the rationale behind acetylene removal and the results of separation testing with both materials

Evaluation of Sorbents for Acetylene Separation in Atmosphere Revitalization Loop Closure

NASA Technical Reports Server (NTRS)

Abney, Morgan B.; Miller, Lee A.; Barton, Katherine

2011-01-01

State-of-the-art carbon dioxide reduction technology uses a Sabatier reactor to recover water from metabolic carbon dioxide. In order to maximize oxygen loop closure, a byproduct of the system, methane, must be reduced to recover hydrogen. NASA is currently exploring a microwave plasma methane pyrolysis system for this purpose. The resulting product stream of this technology includes unreacted methane, product hydrogen, and acetylene. The hydrogen and the small amount of unreacted methane resulting from the pyrolysis process can be returned to the Sabatier reactor thereby substantially improving the overall efficiency of the system. However, the acetylene is a waste product that must be removed from the pyrolysis product. Two materials have been identified as potential sorbents for acetylene removal: zeolite 4A, a commonly available commercial sorbent, and HKUST-1, a newly developed microporous metal. This paper provides an explanation of the rationale behind acetylene removal and the results of separation testing with both materials.

Enhanced methane yield by co-digestion of sewage sludge with micro-algae and catering waste leachate.

PubMed

2018-04-04

The co-digestion of different wastes is a promising concept to improve methane generation during anaerobic process. However, the anaerobic co-digestion of catering waste leachate with algal biomass and sewage sludge has not been studied to date. This work investigated the methane generation by the anaerobic co-digestion of different mixtures of catering waste leachate, micro-algal biomass, and sewage sludge. Co-digestion of waste mixture containing equal ratios of three substrates had 39.31% higher methane yield than anaerobic digestion of raw sludge. This was possibly due to a proliferation of methanogens during the co-digestion period induced by multi-phase digestion of different wastes with different degrees of digestibility. Therefore, co-digestion of catering waste leachate, micro-algal biomass, and sewage sludge appears to be an efficient technology for energy conversion from waste resources. The scientific application of this co-digestion technology with these three substrates may play a role in solving important environmental issues of waste management.

Design of a 500 lbf liquid oxygen and liquid methane rocket engine for suborbital flight

NASA Astrophysics Data System (ADS)

Trillo, Jesus Eduardo

Liquid methane (LCH4)is the most promising rocket fuel for our journey to Mars and other space entities. Compared to liquid hydrogen, the most common cryogenic fuel used today, methane is denser and can be stored at a more manageable temperature; leading to more affordable tanks and a lighter system. The most important advantage is it can be produced from local sources using in-situ resource utilization (ISRU) technology. This will allow the production of the fuel needed to come back to earth on the surface of Mars, or the space entity being explored, making the overall mission more cost effective by enabling larger usable mass. The major disadvantage methane has over hydrogen is it provides a lower specific impulse, or lower rocket performance. The UTEP Center for Space Exploration and Technology Research (cSETR) in partnership with the National Aeronautics and Space Administration (NASA) has been the leading research center for the advancement of Liquid Oxygen (LOX) and Liquid Methane (LCH4) propulsion technologies. Through this partnership, the CROME engine, a throattable 500 lbf LOX/LCH4 rocket engine, was designed and developed. The engine will serve as the main propulsion system for Daedalus, a suborbital demonstration vehicle being developed by the cSETR. The purpose of Daedalus mission and the engine is to fire in space under microgravity conditions to demonstrate its restartability. This thesis details the design process, decisions, and characteristics of the engine to serve as a complete design guide.

Evaluation of Phytoremediation of Coal Bed Methane Product Water and Waters of Quality Similar to that Associated with Coal Bed Methane Reserves of the Powder River Basin, Montana and Wyoming

DOE Office of Scientific and Technical Information (OSTI.GOV)

James Bauder

U.S. emphasis on domestic energy independence, along with advances in knowledge of vast biogenically sourced coalbed methane reserves at relatively shallow sub-surface depths with the Powder River Basin, has resulted in rapid expansion of the coalbed methane industry in Wyoming and Montana. Techniques have recently been developed which constitute relatively efficient drilling and methane gas recovery and extraction techniques. However, this relatively efficient recovery requires aggressive reduction of hydrostatic pressure within water-saturated coal formations where the methane is trapped. Water removed from the coal formation during pumping is typically moderately saline and sodium-bicarbonate rich, and managed as an industrial wastemore » product. Current approaches to coalbed methane product water management include: surface spreading on rangeland landscapes, managed irrigation of agricultural crop lands, direct discharge to ephermeral channels, permitted discharge of treated and untreated water to perennial streams, evaporation, subsurface injection at either shallow or deep depths. A Department of Energy-National Energy Technology Laboratory funded research award involved the investigation and assessment of: (1) phytoremediation as a water management technique for waste water produced in association with coalbed methane gas extraction; (2) feasibility of commercial-scale, low-impact industrial water treatment technologies for the reduction of salinity and sodicity in coalbed methane gas extraction by-product water; and (3) interactions of coalbed methane extraction by-product water with landscapes, vegetation, and water resources of the Powder River Basin. Prospective, greenhouse studies of salt tolerance and water use potential of indigenous, riparian vegetation species in saline-sodic environments confirmed the hypothesis that species such as Prairie cordgrass, Baltic rush, American bulrush, and Nuttall's alkaligrass will thrive in saline-sodic environments when water supplies sourced from coalbed methane extraction are plentiful. Constructed wetlands, planted to native, salt tolerant species demonstrated potential to utilize substantial volumes of coalbed methane product water, although plant community transitions to mono-culture and limited diversity communities is a likely consequence over time. Additionally, selected, cultured forage quality barley varieties and native plant species such as Quail bush, 4-wing saltbush, and seaside barley are capable of sustainable, high quality livestock forage production, when irrigated with coalbed methane product water sourced from the Powder River Basin. A consequence of long-term plant water use which was enumerated is elevated salinity and sodicity concentrations within soil and shallow alluvial groundwater into which coalbed methane product water might drain. The most significant conclusion of these investigations was the understanding that phytoremediation is not a viable, effective technique for management of coalbed methane product water under the present circumstances of produced water within the Powder River Basin. Phytoremediation is likely an effective approach to sodium and salt removal from salt-impaired sites after product water discharges are discontinued and site reclamation is desired. Coalbed methane product water of the Powder River Basin is most frequently impaired with respect to beneficial use quality by elevated sodicity, a water quality constituent which can cause swelling, slaking, and dispersion of smectite-dominated clay soils, such as commonly occurring within the Powder River Basin. To address this issue, a commercial-scale fluid-bed, cationic resin exchange treatment process and prototype operating treatment plant was developed and beta-tested by Drake Water Technologies under subcontract to this award. Drake Water Technologies secured U.S. Patent No. 7,368,059-B2, 'Method for removal of benevolent cations from contaminated water', a beta Drake Process Unit (DPU) was developed and deployed for operation in the Powder River Basin. First year operation demonstrated an 84% sodium removal capacity. Greenhouse, laboratory and field research documented substantial likelihood of measurable alteration in soil chemistry, soil physical properties, and shallow alluvial aquifers in and below areas of sustained surface application through irrigation or water spreading or impoundment of coalbed methane product water in evaporation reservoirs within the Basin. Events of repeated wetting and drying of agricultural soils characteristic of the Powder River Basin with coalbed methane product water, followed by infrequent rainfall events, presents high probability circumstances of significant reductions in infiltration capacity and hydraulic conductivity of agricultural soils containing more than 34% smectite clay.« less

The rumen microbial metagenome associated with high methane production in cattle.

PubMed

Wallace, R John; Rooke, John A; McKain, Nest; Duthie, Carol-Anne; Hyslop, Jimmy J; Ross, David W; Waterhouse, Anthony; Watson, Mick; Roehe, Rainer

2015-10-23

Methane represents 16 % of total anthropogenic greenhouse gas emissions. It has been estimated that ruminant livestock produce ca. 29 % of this methane. As individual animals produce consistently different quantities of methane, understanding the basis for these differences may lead to new opportunities for mitigating ruminal methane emissions. Metagenomics is a powerful new tool for understanding the composition and function of complex microbial communities. Here we have applied metagenomics to the rumen microbial community to identify differences in the microbiota and metagenome that lead to high- and low-methane-emitting cattle phenotypes. Four pairs of beef cattle were selected for extreme high and low methane emissions from 72 animals, matched for breed (Aberdeen-Angus or Limousin cross) and diet (high or medium concentrate). Community analysis was carried out by qPCR of 16S and 18S rRNA genes and by alignment of Illumina HiSeq reads to the GREENGENES database. Total genomic reads were aligned to the KEGG genes databasefor functional analysis. Deep sequencing produced on average 11.3 Gb per sample. 16S rRNA gene abundances indicated that archaea, predominantly Methanobrevibacter, were 2.5× more numerous (P = 0.026) in high emitters, whereas among bacteria Proteobacteria, predominantly Succinivibrionaceae, were 4-fold less abundant (2.7 vs. 11.2 %; P = 0.002). KEGG analysis revealed that archaeal genes leading directly or indirectly to methane production were 2.7-fold more abundant in high emitters. Genes less abundant in high emitters included acetate kinase, electron transport complex proteins RnfC and RnfD and glucose-6-phosphate isomerase. Sequence data were assembled de novo and over 1.5 million proteins were annotated on the subsequent metagenome scaffolds. Less than half of the predicted genes matched matched a domain within Pfam. Amongst 2774 identified proteins of the 20 KEGG orthologues that correlated with methane emissions, only 16 showed 100 % identity with a publicly available protein sequence. The abundance of archaeal genes in ruminal digesta correlated strongly with differing methane emissions from individual animals, a finding useful for genetic screening purposes. Lower emissions were accompanied by higher Succinovibrionaceae abundance and changes in acetate and hydrogen production leading to less methanogenesis, as similarly postulated for Australian macropods. Large numbers of predicted protein sequences differed between high- and low-methane-emitting cattle. Ninety-nine percent were unknown, indicating a fertile area for future exploitation.

Estimation of Methane Emissions from Slurry Pits below Pig and Cattle Confinements

PubMed Central

Petersen, Søren O.; Olsen, Anne B.; Elsgaard, Lars; Triolo, Jin Mi; Sommer, Sven G.

2016-01-01

Quantifying in-house emissions of methane (CH4) from liquid manure (slurry) is difficult due to high background emissions from enteric processes, yet of great importance for correct estimation of CH4 emissions from manure management and effects of treatment technologies such as anaerobic digestion. In this study CH4 production rates were determined in 20 pig slurry and 11 cattle slurry samples collected beneath slatted floors on six representative farms; rates were determined within 24 h at temperatures close to the temperature in slurry pits at the time of collection. Methane production rates in pig and cattle slurry differed significantly at 0.030 and 0.011 kg CH4 kg-1 VS (volatile solids). Current estimates of CH4 emissions from pig and cattle manure management correspond to 0.032 and 0.015 kg CH4 kg-1, respectively, indicating that slurry pits under animal confinements are a significant source. Fractions of degradable volatile solids (VSd, kg kg-1 VS) were estimated using an aerobic biodegradability assay and total organic C analyses. The VSd in pig and cattle slurry averaged 0.51 and 0.33 kg kg-1 VS, and it was estimated that on average 43 and 28% of VSd in fresh excreta from pigs and cattle, respectively, had been lost at the time of sampling. An empirical model of CH4 emissions from slurry was reparameterised based on experimental results. A sensitivity analysis indicated that predicted CH4 emissions were highly sensitive to uncertainties in the value of lnA of the Arrhenius equation, but much less sensitive to uncertainties in VSd or slurry temperature. A model application indicated that losses of carbon in VS as CO2 may be much greater than losses as CH4. Implications of these results for the correct estimation of CH4 emissions from manure management, and for the mitigation potential of treatments such as anaerobic digestion, are discussed. PMID:27529692

Solid waste treatment as a high-priority and low-cost alternative for greenhouse gas mitigation.

PubMed

Ayalon, O; Avnimelech, Y; Shechter, M

2001-05-01

The increased concern about environmental problems caused by inadequate waste management, as well as the concern about global warming, promotes actions toward a sustainable management of the organic fraction of the waste. Landfills, the most common means to dispose of municipal solid waste (MSW), lead to the conversion of the organic waste to biogas, containing about 50% methane, a very active greenhouse gas (GHG). One unit of methane has a global warming potential of 21 computed for a 100-year horizon or 56 computed for 20 years. The waste sector in Israel contributes 13% of total greenhouse gases (GHG) emissions for a time horizon of 100 years (for a time horizon of 20 years, the waste sector contribution equals to more than 25% of total GHG emissions). The ultimate goal is to minimize the amount of methane (CH4) by converting it to CO2. This can be achieved by physicochemical means (e.g., landfill gas flare, incineration) or by biological processes (e.g., composting, anaerobic digestion). Since the waste in Israel has a high organic material content, it was found that the most cost-effective means to treat the degradable organic components is by aerobic composting (investment of less than US$ 10 to reduce emission of one ton CO2 equivalent per year). Another benefit of this technology is the ability to implement it within a short period. The suggested approach, which should be implemented especially in developing countries, could reduce a significant amount of GHG at relatively low cost and short time. The development of a national policy for proper waste treatment can be a significant means to abate GHG emissions in the short term, enabling a gain in time to develop other means for the long run. In addition, the use of CO2 quotas will credit the waste sector and will promote profitable proper waste management.

Dry reforming of methane to syngas: a potential alternative process for value added chemicals-a techno-economic perspective.

PubMed

Mondal, Kartick; Sasmal, Sankar; Badgandi, Srikant; Chowdhury, Dipabali Roy; Nair, Vinod

2016-11-01

During the past decade, there has been increasing global concern over the rise of anthropogenic CO 2 emission into the Earth's atmosphere (J Air Waste Manage Assoc 53:645-715, 2003). The utilization of CO 2 to produce any valuable product is need of the hour. The production of syngas from CO 2 and CH 4 seems to be one of the promising alternatives in terms of industrial utilization, as it offers several advantages: (a) mitigation of CO 2 , (b) transformation of natural gas and CO 2 into valuable syngas, and (c) producing syngas with H 2 /CO ratio 1 which may further be used for the production of valuable petrochemicals (J Air Waste Manage Assoc 53:645-715, 2003). A conceptual design for the production of synthesis gas by dry reforming of methane is presented here. An economic assessment of this process with an integrated methanol production section as a case was conceptualized and compared with the conventional steam methane reforming route to produce methanol. The economic study indicated that dry reforming of natural gas/methane is a competitive process with lower operating and capital costs in comparison with steam reforming assuming negligible cost of CO 2 import.

Effect of ferrihydrite biomineralization on methanogenesis in an anaerobic incubation from paddy soil

NASA Astrophysics Data System (ADS)

Zhuang, Li; Xu, Jielong; Tang, Jia; Zhou, Shungui

2015-05-01

Microbial reduction of Fe(III) can be one of the major factors controlling methane production from anaerobic sedimentary environments, such as paddy soils and wetlands. Although secondary iron mineralization following Fe(III) reduction is a process that occurs naturally over time, it has not yet been considered in methanogenic systems. This study performed a long-term anaerobic incubation of a paddy soil and ferrihydrite-supplemented soil cultures to investigate methanogenesis during ferrihydrite biomineralization. The results revealed that the long-term effect of ferrihydrite on methanogenesis may be enhancement rather than suppression documented in previous studies. During initial microbial ferrihydrite reduction, methanogenesis was suppressed; however, the secondary minerals of magnetite formation was simultaneous with facilitated methanogenesis in terms of average methane production rate and acetate utilization rate. In the phase of magnetite formation, microbial community analysis revealed a strong stimulation of the bacterial Geobacter, Bacillus, and Sedimentibacter and the archaeal Methanosarcina in the ferrihydrite-supplemented cultures. Direct electric syntrophy between Geobacter and Methanosarcina via conductive magnetite is the plausible mechanism for methanogenesis acceleration along with magnetite formation. Our data suggested that a change in iron mineralogy might affect the conversion of anaerobic organic matter to methane and might provide a fresh perspective on the mitigation of methane emissions from paddy soils by ferric iron fertilization.

Remote sensing of methane with OSAS-lidar on the 2ν3 band Q-branch: Experimental proof

NASA Astrophysics Data System (ADS)

Galtier, Sandrine; Anselmo, Christophe; Welschinger, Jean-Yves; Sivignon, J. F.; Cariou, Jean-Pierre; Miffre, Alain; Rairoux, Patrick

2018-06-01

Optical sensors based on absorption spectroscopy play a central role in the detection and monitoring of atmospheric trace gases. We here present for the first time the experimental demonstration of OSAS-Lidar on the remote sensing of CH4 in the atmosphere. This new methodology, the OSAS-Lidar, couples the Optical Similitude Absorption Spectroscopy (OSAS) methodology with a light detection and ranging device. It is based on the differential absorption of spectrally integrated signals following Beer Lambert-Bouguer law, which are range-resolved. Its novelty originates from the use of broadband laser spectroscopy and from the mathematical approach used to retrieve the trace gas concentration. We previously applied the OSAS methodology in laboratory on the 2ν3 methane absorption band, centered at the 1665 nm wavelength and demonstrated that the OSAS-methodology is almost independent from atmospheric temperature and pressure. In this paper, we achieve an OSAS-Lidar device capable of observing large concentrations of CH4 released from a methane source directly into the atmosphere. Comparison with a standard in-situ measurement device shows that the path-integrated concentrations retrieved from OSAS-Lidar methodology exhibit sufficient sensitivity (2 000 ppm m) and observational time resolution (1 s) to remotely sense methane leaks in the atmosphere. The coupling of OSAS-lidar with a wind measurement device opens the way to monitor time-resolved methane flux emissions, which is important in regards to future climate mitigation involving regional reduction of CH4 flux emissions.

Quantifying Industrial Methane Emissions from Space with the GHGSat-D Satellite

NASA Astrophysics Data System (ADS)

Germain, S.; Durak, B.; Gains, D.; Jervis, D.; McKeever, J.; Sloan, J. J.

2017-12-01

In June 2016, GHGSat, Inc. launched GHGSat-D, or "Claire", the world's first satellite capable of measuring greenhouse gas emissions from targeted industrial facilities around the world. The high-level objective of this mission is to demonstrate that a single measurement approach can quantify methane emission rates from selected industrial sources with greater precision, higher frequency, and lower cost than ground-based alternatives, across a wide range of industries. Providing industrial operators and regulators with frequent, cost-effective emission measurements can help identify super-emitters and monitor the progress of mitigation efforts. The GHGSat measurement platform is a 15 kg satellite that measures methane column densities using a novel wide-angle imaging Fabry-Perot spectrometer tuned to the 1600-1700 nm SWIR band. During each measurement sequence, a series of closely overlapping 2D images are taken so that each ground location samples a portion of the SWIR band with 0.1 nm spectral resolution. The data processing algorithm is able to co-register each image and, by comparison with a detailed forward model, perform a retrieval on each of the <50 m GSD over the entire 12 x 12 km2 field of view. Methane emission rates are then estimated using a dispersion model coupled with locally measured wind fields. We will present the economic rationale for satellite-based sensing of methane from industrial sources, introduce the GHGSat measurement concept, report on recent measurement results obtained by Claire, and describe performance upgrades planned for future missions.

Optical fiber network sensor system for monitoring methane concentration

NASA Astrophysics Data System (ADS)

Zhang, Zhi-wei; Zhang, Ji-long

2011-08-01

With regard to the high accuracy optic-fiber sensor for monitoring methane concentration, the choice of light source depends on methane peak values. Besides, the environment of mine should be considered, that is to say other gas should be considered, such as vapor, CO and CO2 etc, without absorbent spectrum in the decided wavelength. It has been reported that vapor, CO and CO2 have no obvious absorption in 0.85μm, 1.3μm and 1.66μm area, CH4 has no obvious absorption in 0.85μm area. So diode laser with 1.3μm or 1.66μm peak wavelength is chosen as the optic-fiber sensor's light source for detecting methane concentration. On the basis of the principle of optic absorption varied with methane concentration at its characteristic absorbent wavelength, the advantage of optic-fiber sensor technology and the circumstance characteristic of the coal mine. An optic-fiber sensor system is presented for monitoring methane concentration. Space Division Multiple Access Technology (SDMAT) and long optical path absorbent pool technology are combined in the study. Considering the circumstance characteristic of the coal mine, the optic-fiber network sensors for detecting methane concentration from mix gas of vapor, CO, CH4 and CO2 are used. It introduces the principle of an optic-fiber sensor system for monitoring methane concentration in coal mine. It contains the structure block diagram of monitoring system, the system is mainly made up of diode laser for monitoring methane concentration, Y-shaped photo-coupler with coupled rate 50:50, optical switch 1×2, gas absorbent cell, the computer data process and control system and photoelectric transformer. In this study, in order to decrease to the influence of the dark-current of photodiode, intensity in light sources and temperature drifts of processing circuit on the system accuracy in measurement, a beam of light is broken down into two beams in the coupler of Y-shaped coupler, the one acts as the reference optical path, the other is known as the sensing optical path. The experimental result shows that diode laser with 1654.141nm in wavelength is taken as the optic source for detecting methane concentration, the detective limit of the sensor is below 4.274mg/m3 when the optical path of absorbent pool is 20 centimeters, and the prevision and stability could satisfy practical application. The whole instrument can also reach on-line measurement with multiple points on different spot.

MERLIN: a Franco-German LIDAR space mission for atmospheric methane

NASA Astrophysics Data System (ADS)

Bousquet, P.; Ehret, G.; Pierangelo, C.; Marshall, J.; Bacour, C.; Chevallier, F.; Gibert, F.; Armante, R.; Crevoisier, C. D.; Edouart, D.; Esteve, F.; Julien, E.; Kiemle, C.; Alpers, M.; Millet, B.

2017-12-01

The Methane Remote Sensing Lidar Mission (MERLIN), currently in phase C, is a joint cooperation between France and Germany on the development, launch and operation of a space LIDAR dedicated to the retrieval of total weighted methane (CH4) atmospheric columns. Atmospheric methane is the second most potent anthropogenic greenhouse gas, contributing 20% to climate radiative forcing but also plying an important role in atmospheric chemistry as a precursor of tropospheric ozone and low-stratosphere water vapour. Its short lifetime ( 9 years) and the nature and variety of its anthropogenic sources also offer interesting mitigation options in regards to the 2° objective of the Paris agreement. For the first time, measurements of atmospheric composition will be performed from space thanks to an IPDA (Integrated Path Differential Absorption) LIDAR (Light Detecting And Ranging), with a precision (target ±27 ppb for a 50km aggregation along the trace) and accuracy (target <3.7 ppb at 68%) sufficient to significantly reduce the uncertainties on methane emissions. The very low targeted systematic error target is particularly ambitious compared to current passive methane space mission. It is achievable because of the differential active measurements of MERLIN, which guarantees almost no contamination by aerosols or water vapour cross-sensitivity. As an active mission, MERLIN will deliver global methane weighted columns (XCH4) for all seasons and all latitudes, day and night Here, we recall the MERLIN objectives and mission characteristics. We also propose an end-to-end error analysis, from the causes of random and systematic errors of the instrument, of the platform and of the data treatment, to the error on methane emissions. To do so, we propose an OSSE analysis (observing system simulation experiment) to estimate the uncertainty reduction on methane emissions brought by MERLIN XCH4. The originality of our inversion system is to transfer both random and systematic errors from the observation space to the flux space, thus providing more realistic error reductions than usually provided in OSSE only using the random part of errors. Uncertainty reductions are presented using two different atmospheric transport models, TM3 and LMDZ, and compared with error reduction achieved with the GOSAT passive mission.

Global and Regional Temperature-change Potentials for Near-term Climate Forcers

NASA Technical Reports Server (NTRS)

Collins, W.J.; Fry, M. M.; Yu, H.; Fuglestvedt, J. S.; Shindell, D. T.; West, J. J.

2013-01-01

The emissions of reactive gases and aerosols can affect climate through the burdens of ozone, methane and aerosols, having both cooling and warming effects. These species are generally referred to near-term climate forcers (NTCFs) or short-lived climate pollutants (SLCPs), because of their short atmospheric residence time. The mitigation of these would be attractive for both air quality and climate on a 30-year timescale, provided it is not at the expense of CO2 mitigation. In this study we examine the climate effects of the emissions of NTCFs from 4 continental regions (East Asia, Europe, North America and South Asia) using results from the Task Force on Hemispheric Transport of Air Pollution Source-Receptor global chemical transport model simulations. We address 3 aerosol species (sulphate, particulate organic matter and black carbon - BC) and 4 ozone precursors (methane, reactive nitrogen oxides - NOx, volatile organic compounds VOC, and carbon monoxide - CO). For the aerosols the global warming potentials (GWPs) and global temperature change potentials (GTPs) are simply time-dependent scaling of the equilibrium radiative forcing, with the GTPs decreasing more rapidly with time than the GWPs. While the aerosol climate metrics have only a modest dependence on emission region, emissions of NOx and VOCs from South Asia have GWPs and GTPs of higher magnitude than from the other northern hemisphere regions. On regional basis, the northern mid-latitude temperature response to northern mid-latitude emissions is approximately twice as large as the global average response for aerosol emission, and about 20-30% larger than the global average for methane, VOC and CO emissions. We also found that temperatures in the Arctic latitudes appear to be particularly sensitive to black carbon emissions from South Asia.

Preface to the special issue on gas hydrate drilling in the Eastern Nankai Trough

USGS Publications Warehouse

Yamamoto, Koji; Ruppel, Carolyn D.

2015-01-01

Methane hydrate traps enormous amounts of methane in frozen deposits in continental margin sediments, and these deposits have long been targeted for studies investigating their potential as an energy resource. As a concentrated form of methane that occurs at shallower depths than conventional and most unconventional gas reservoirs, methane hydrates could be a readily accessible source of hydrocarbons for countries hosting deposits within their Exclusive Economic Zones. Japan is one such country, and since 2001 the Research Consortium for Methane Hydrate Resources in Japan (referred to as MH21) has conducted laboratory, modeling, and field-based programs to study methane hydrates as an energy resource. The MH21 consortium is funded by the Japanese Ministry of Trade and Industry (METI) and led by the Japan Oil, Gas and Metals National Oil Corporation (JOGMEC) and the National Institute of Advanced Industrial Science and Technology (AIST).

Methane Hydrate in Confined Spaces: An Alternative Storage System.

PubMed

Borchardt, Lars; Casco, Mirian Elizabeth; Silvestre-Albero, Joaquin

2018-06-05

Methane hydrate inheres the great potential to be a nature-inspired alternative for chemical energy storage, as it allows to store large amounts of methane in a dense solid phase. The embedment of methane hydrate in the confined environment of porous materials can be capitalized for potential applications as its physicochemical properties, such as the formation kinetics or pressure and temperature stability, are significantly changed compared to the bulk system. We review this topic from a materials scientific perspective by considering porous carbons, silica, clays, zeolites, and polymers as host structures for methane hydrate formation. We discuss the contribution of advanced characterization techniques and theoretical simulations towards the elucidation of the methane hydrate formation and dissociation process within the confined space. We outline the scientific challenges this system is currently facing and look on possible future applications for this technology. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Reduction of ruminant methane emissions - a win-win-win opportunity for business, development, and the environment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Livingston, R.

1997-12-31

This paper describes research efforts of The Global Livestock Producers Program (GLPP) in establishing self-sustaining enterprises for cost-effective technologies (i.e., animal nutrition and genetic improvement) and global methane emissions reductions in developing world nations. The US Environmental Protection Agency has funded several studies to examine the possibilities of reducing ruminant methane emissions in India, Tanzania, Bangladesh, and Brazil. The results of the studies showed that: (1) many developing countries` production systems are inefficient, and (2) great potential exists for decreasing global methane emissions through increasing animal productivity. From this effort, the GLPP established livestock development projects in India, Zimbabwe, andmore » Tanzania, and is developing projects for Bangladesh, Nepal, and Brazil. The GLPP has developed a proven methodology for assessing ruminant methane and incorporating methane emissions monitoring into viable projects.« less

Feeling bogged down about climate change mitigation? Insights from a new high resolution peatland-bog model validated at two Dutch monitoring sites.

NASA Astrophysics Data System (ADS)

Lippmann, Tanya; van Huissteden, Ko; Hendriks, Dimmie

2017-04-01

Increasing the global carbon sink is one of two options to mitigate CO2 and CH4 increases in the atmosphere (the other is emissions reductions at the source). Peatlands release carbon to the atmosphere when disturbed by natural or human causes and absorb carbon when vegetation and soil organic matter accumulate after rewetting or natural revegetation. However, rewetting of drained peatlands is frequently not considered as a climate mitigation strategy due to the enhanced methane emissions that accompany newly formed anaerobic peatland environments. We hypothesise that at most sites, this trend will be temporal but long-term, lasting for tens of years post re-wetting before stabilisation takes place. This study investigates the ability of rewetted peatland sites to act as either a source or sink for atmospheric methane and carbon dioxide under climate change. The hydrology of a peatland is fundamental to its functioning. Therefore, the use of a full water balance table has the potential to simulate greenhouse gas fluxes to a greater degree of certainty. MODFLOW is the internationally most widely used ground and surface water model and is freely available to the scientific community. This is the first time that a gridded peatland process based model has been constructed at a spatial resolution as high as 25m x 25m. This new high-resolution model allows for investigation into the complex biophysical and hydrological factors that are necessary to reliably estimate atmospheric greenhouse gas fluxes in a peatland ecosystem. We assess the model's skill against observations collected at two monitoring sites of differing soil properties and vegetation in the Netherlands. These results discuss site-specific suitability of peatland regeneration, useful for climate change mitigation activities. Aside from the insight into transient atmosphere-peatland carbon fluxes, this work is a stepping stone towards more robust model coupling and greater spatial coverage.

Developing a Methodology for Risk-Informed Trade-Space Analysis in Acquisition

DTIC Science & Technology

2015-01-01

73 6.10. Research, Development, Test, and Evaluation Cost Distribution, Technology 1 Mitigation of...6.11. Research, Development, Test, and Evaluation Cost Distribution, Technology 3 Mitigation of the Upgrade Alternative...courses of action, or risk- mitigation behaviors, which take place in the event that the technology is not developed by the mile- stone date (e.g

Cryogenic Fluid Storage Technology Development: Recent and Planned Efforts at NASA

NASA Technical Reports Server (NTRS)

Moran, Matthew E.

2009-01-01

Recent technology development work conducted at NASA in the area of Cryogenic Fluid Management (CFM) storage is highlighted, including summary results, key impacts, and ongoing efforts. Thermodynamic vent system (TVS) ground test results are shown for hydrogen, methane, and oxygen. Joule-Thomson (J-T) device tests related to clogging in hydrogen are summarized, along with the absence of clogging in oxygen and methane tests. Confirmation of analytical relations and bonding techniques for broad area cooling (BAC) concepts based on tube-to-tank tests are presented. Results of two-phase lumped-parameter computational fluid dynamic (CFD) models are highlighted, including validation of the model with hydrogen self pressurization test data. These models were used to simulate Altair representative methane and oxygen tanks subjected to 210 days of lunar surface storage. Engineering analysis tools being developed to support system level trades and vehicle propulsion system designs are also cited. Finally, prioritized technology development risks identified for Constellation cryogenic propulsion systems are presented, and future efforts to address those risks are discussed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, M.L.

This paper very briefly summarizes progress in the demonstration of a small (up to 6 MWe), environmentally acceptable electric generating system fueled by indigenous fuels and waste materials to serve power distribution systems typical of Alaskan Native communities. Two detailed appendices supplement the report. The project is focused on two primary technologies: (1) atmospheric fluidized bed combustion (AFBC), and (2) coalbed methane and coal-fired diesel technologies. Two sites have been selected as possible locations for an AFBC demonstration, and bid proposals are under review. The transfer of a coal-fired diesel clean coal demonstration project from Maryland to Fairbanks, Alaska wasmore » approved, and the environmental assessment has been initiated. Federal support for a fuel cell using coalbed methane is also being pursued. The appendices included in the report provide: (1) the status of the conceptual design study for a 600-kWe coal-fired cogeneration plant in McGrath, Alaska; and (2) a global market assessment of coalbed methane, fluidized-bed combustion, and coal-fired diesel technologies in remote applications.« less

Methane, benzene and alkyl benzene cold start emission data of gasoline-driven passenger cars representing the vehicle technology of the last two decades

NASA Astrophysics Data System (ADS)

Heeb, Norbert V.; Forss, Anna-Maria; Saxer, Christian J.; Wilhelm, Patrick

The US urban driving cycle (FTP-75) is widely used to estimate both the emissions under hot engine conditions as well as those associated with the cold start. Applying fast analysis techniques such as chemical ionization mass spectrometry (CI-MS) the warm-up behavior of individual vehicles can be monitored at a time resolution of 1 s. CI-MS has been used to investigate the emissions of methane, benzene and the alkyl benzene class of compounds. The amount of the emissions at cold start influence was deduced from the time-resolved emission data of four gasoline-driven vehicle classes representing the vehicle technology of the last two decades. Overall, the emissions of five EURO-0, 20 EURO-1, 18 EURO-2 and so far of six EURO-3 passenger cars were recorded. The test vehicles were selected from the currently operating Swiss car fleet based on the car sales statistics. The average methane, benzene and alkyl benzene cold start emissions are reported using both, the traditional bag method as well as the regression model. At room temperature a clear reduction of 94%, 81% and 85% was found for the methane, benzene and alkyl benzene cold start emissions from EURO-0 to EURO-3 technology, respectively.

Assessment of environmental health and safety issues associated with the commercialization of unconventional gas recovery: methane from coal seams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ethridge, L.J.; Cowan, C.E.; Riedel, E.F.

1980-07-01

Potential public health and safety problems and the potential environmental impacts from the recovery of gas from coalbeds are identified and examined. The technology of methane recovery is described and economic and legal barriers to production are discussed. (ACR)

Robust IR Remote Sensing Technique of the Total Column of Trace Gases Including Carbon Dioxide and Methane

NASA Technical Reports Server (NTRS)

Georgieva, E. M.; Heaps, W. S.

2011-01-01

Progress on the development of a differential radiometer based upon the Fabry-Perot interferometer (FPI) for methane (CH4) and carbon dioxide (C02) detection in the atmosphere is presented. Methane measurements are becoming increasingly important as a component of NASA's programs to understand the global carbon cycle and quantifY the threat of global warming. Methane is the third most important greenhouse gas in the Earth's radiation budget (after water vapor and carbon dioxide) and the second most important anthropogenic contributor to global warming. The importance of global warming and air quality to society caused the National Research Council to recommend that NASA develop the following missions [1]: ASCENDS (Active Sensing of C02 Emissions over Nights, Days, and Seasons), GEOCAPE (Geostationary Coastal and Air Pollution Events), and GACM (Global Atmosphere Composition Mission). Though methane measurements are not specifically called out in these missions, ongoing environmental changes have raised the importance of understanding the methane budget. In the decadal survey is stated that "to close the carbon budget, we would also address methane, but the required technology is not obvious at this time. If appropriate and cost-effective methane technology becomes available, we strongly recommend adding a methane capability". In its 2007 report the International Panel on Climate Change identified methane as a key uncertainty in our understanding saying that the causes of recent changes in the growth rate of atmospheric CH4 are not well understood. What we do know is that methane arises from a number of natural sources including wet lands and the oceans plus man made sources from agriculture, as well as coal and petroleum production and distribution. It has recently been pointed out that large amount of methane are frozen in the permafrost of Canada and Siberia. There is a fear that melting of this permafrost driven by global warming may release large amounts of methane very suddenly further exacerbating climate change [2]. Last year our group began a joint effort with Johns Hopkins Applied Physics Laboratory to investigate the possibility of developing a small unmanned aerial vehicle (UAV) equipped to measure greenhouse gases-particularly methane. Although we are targeting our system for smaller UAV's the instrument will be directly applicable to missions involving larger NASA UAV's such as Global Hawk or even on missions utilizing manned aircraft. Because of its small size, inherent ruggedness and simplicity some version of our proposed instrument may find a role as a satellite instrument for NASA or NOAA.

Mathematical modeling of the gas extraction from the gas hydrate deposit taking into account the replacement technology

NASA Astrophysics Data System (ADS)

Musakaev, N. G.; Khasanov, M. K.; Borodin, S. L.

2018-03-01

In the work on the basis of methods and equations of mechanics of multiphase systems the mathematical model of the process of carbon dioxide burial in the reservoir saturated with methane hydrate is proposed. Estimates are obtained that allow for this problem to neglect diffusion mixing of carbon dioxide and methane. The features of the process of methane displacement from CH4 hydrate by filling them with carbon dioxide are studied.

Polyhydroxyalkanoates in waste activated sludge enhances anaerobic methane production through improving biochemical methane potential instead of hydrolysis rate.

PubMed

Wang, Qilin; Sun, Jing; Zhang, Chang; Xie, Guo-Jun; Zhou, Xu; Qian, Jin; Yang, Guojing; Zeng, Guangming; Liu, Yiqi; Wang, Dongbo

2016-01-21

Anaerobic sludge digestion is the main technology for sludge reduction and stabilization prior to sludge disposal. Nevertheless, methane production from anaerobic digestion of waste activated sludge (WAS) is often restricted by the poor biochemical methane potential and slow hydrolysis rate of WAS. This work systematically investigated the effect of PHA levels of WAS on anaerobic methane production, using both experimental and mathematical modeling approaches. Biochemical methane potential tests showed that methane production increased with increased PHA levels in WAS. Model-based analysis suggested that the PHA-based method enhanced methane production by improving biochemical methane potential of WAS, with the highest enhancement being around 40% (from 192 to 274 L CH4/kg VS added; VS: volatile solid) when the PHA levels increased from 21 to 143 mg/g VS. In contrast, the hydrolysis rate (approximately 0.10 d(-1)) was not significantly affected by the PHA levels. Economic analysis suggested that the PHA-based method could save $1.2/PE/y (PE: population equivalent) in a typical wastewater treatment plant (WWTP). The PHA-based method can be easily integrated into the current WWTP to enhance methane production, thereby providing a strong support to the on-going paradigm shift in wastewater management from pollutant removal to resource recovery.

Zero valent iron significantly enhances methane production from waste activated sludge by improving biochemical methane potential rather than hydrolysis rate.

PubMed

Liu, Yiwen; Wang, Qilin; Zhang, Yaobin; Ni, Bing-Jie

2015-02-05

Anaerobic digestion has been widely applied for waste activated sludge (WAS) treatment. However, methane production from anaerobic digestion of WAS is usually limited by the slow hydrolysis rate and/or poor biochemical methane potential of WAS. This work systematically studied the effects of three different types of zero valent iron (i.e., iron powder, clean scrap and rusty scrap) on methane production from WAS in anaerobic digestion, by using both experimental and mathematical approaches. The results demonstrated that both the clean and the rusty iron scrap were more effective than the iron powder for improving methane production from WAS. Model-based analysis showed that ZVI addition significantly enhanced methane production from WAS through improving the biochemical methane potential of WAS rather than its hydrolysis rate. Economic analysis indicated that the ZVI-based technology for enhancing methane production from WAS is economically attractive, particularly considering that iron scrap can be freely acquired from industrial waste. Based on these results, the ZVI-based anaerobic digestion process of this work could be easily integrated with the conventional chemical phosphorus removal process in wastewater treatment plant to form a cost-effective and environment-friendly approach, enabling maximum resource recovery/reuse while achieving enhanced methane production in wastewater treatment system.

Zero Valent Iron Significantly Enhances Methane Production from Waste Activated Sludge by Improving Biochemical Methane Potential Rather Than Hydrolysis Rate

PubMed Central

Liu, Yiwen; Wang, Qilin; Zhang, Yaobin; Ni, Bing-Jie

2015-01-01

Anaerobic digestion has been widely applied for waste activated sludge (WAS) treatment. However, methane production from anaerobic digestion of WAS is usually limited by the slow hydrolysis rate and/or poor biochemical methane potential of WAS. This work systematically studied the effects of three different types of zero valent iron (i.e., iron powder, clean scrap and rusty scrap) on methane production from WAS in anaerobic digestion, by using both experimental and mathematical approaches. The results demonstrated that both the clean and the rusty iron scrap were more effective than the iron powder for improving methane production from WAS. Model-based analysis showed that ZVI addition significantly enhanced methane production from WAS through improving the biochemical methane potential of WAS rather than its hydrolysis rate. Economic analysis indicated that the ZVI-based technology for enhancing methane production from WAS is economically attractive, particularly considering that iron scrap can be freely acquired from industrial waste. Based on these results, the ZVI-based anaerobic digestion process of this work could be easily integrated with the conventional chemical phosphorus removal process in wastewater treatment plant to form a cost-effective and environment-friendly approach, enabling maximum resource recovery/reuse while achieving enhanced methane production in wastewater treatment system. PMID:25652244

Polyhydroxyalkanoates in waste activated sludge enhances anaerobic methane production through improving biochemical methane potential instead of hydrolysis rate

PubMed Central

Wang, Qilin; Sun, Jing; Zhang, Chang; Xie, Guo-Jun; Zhou, Xu; Qian, Jin; Yang, Guojing; Zeng, Guangming; Liu, Yiqi; Wang, Dongbo

2016-01-01

Anaerobic sludge digestion is the main technology for sludge reduction and stabilization prior to sludge disposal. Nevertheless, methane production from anaerobic digestion of waste activated sludge (WAS) is often restricted by the poor biochemical methane potential and slow hydrolysis rate of WAS. This work systematically investigated the effect of PHA levels of WAS on anaerobic methane production, using both experimental and mathematical modeling approaches. Biochemical methane potential tests showed that methane production increased with increased PHA levels in WAS. Model-based analysis suggested that the PHA-based method enhanced methane production by improving biochemical methane potential of WAS, with the highest enhancement being around 40% (from 192 to 274 L CH4/kg VS added; VS: volatile solid) when the PHA levels increased from 21 to 143 mg/g VS. In contrast, the hydrolysis rate (approximately 0.10 d−1) was not significantly affected by the PHA levels. Economic analysis suggested that the PHA-based method could save $1.2/PE/y (PE: population equivalent) in a typical wastewater treatment plant (WWTP). The PHA-based method can be easily integrated into the current WWTP to enhance methane production, thereby providing a strong support to the on-going paradigm shift in wastewater management from pollutant removal to resource recovery. PMID:26791952

Zero Valent Iron Significantly Enhances Methane Production from Waste Activated Sludge by Improving Biochemical Methane Potential Rather Than Hydrolysis Rate

NASA Astrophysics Data System (ADS)

Liu, Yiwen; Wang, Qilin; Zhang, Yaobin; Ni, Bing-Jie

2015-02-01

Anaerobic digestion has been widely applied for waste activated sludge (WAS) treatment. However, methane production from anaerobic digestion of WAS is usually limited by the slow hydrolysis rate and/or poor biochemical methane potential of WAS. This work systematically studied the effects of three different types of zero valent iron (i.e., iron powder, clean scrap and rusty scrap) on methane production from WAS in anaerobic digestion, by using both experimental and mathematical approaches. The results demonstrated that both the clean and the rusty iron scrap were more effective than the iron powder for improving methane production from WAS. Model-based analysis showed that ZVI addition significantly enhanced methane production from WAS through improving the biochemical methane potential of WAS rather than its hydrolysis rate. Economic analysis indicated that the ZVI-based technology for enhancing methane production from WAS is economically attractive, particularly considering that iron scrap can be freely acquired from industrial waste. Based on these results, the ZVI-based anaerobic digestion process of this work could be easily integrated with the conventional chemical phosphorus removal process in wastewater treatment plant to form a cost-effective and environment-friendly approach, enabling maximum resource recovery/reuse while achieving enhanced methane production in wastewater treatment system.

Polyhydroxyalkanoates in waste activated sludge enhances anaerobic methane production through improving biochemical methane potential instead of hydrolysis rate

NASA Astrophysics Data System (ADS)

Wang, Qilin; Sun, Jing; Zhang, Chang; Xie, Guo-Jun; Zhou, Xu; Qian, Jin; Yang, Guojing; Zeng, Guangming; Liu, Yiqi; Wang, Dongbo

2016-01-01

Anaerobic sludge digestion is the main technology for sludge reduction and stabilization prior to sludge disposal. Nevertheless, methane production from anaerobic digestion of waste activated sludge (WAS) is often restricted by the poor biochemical methane potential and slow hydrolysis rate of WAS. This work systematically investigated the effect of PHA levels of WAS on anaerobic methane production, using both experimental and mathematical modeling approaches. Biochemical methane potential tests showed that methane production increased with increased PHA levels in WAS. Model-based analysis suggested that the PHA-based method enhanced methane production by improving biochemical methane potential of WAS, with the highest enhancement being around 40% (from 192 to 274 L CH4/kg VS added; VS: volatile solid) when the PHA levels increased from 21 to 143 mg/g VS. In contrast, the hydrolysis rate (approximately 0.10 d-1) was not significantly affected by the PHA levels. Economic analysis suggested that the PHA-based method could save $1.2/PE/y (PE: population equivalent) in a typical wastewater treatment plant (WWTP). The PHA-based method can be easily integrated into the current WWTP to enhance methane production, thereby providing a strong support to the on-going paradigm shift in wastewater management from pollutant removal to resource recovery.

The case for refining bottom-up methane emission inventories using top-down measurements

NASA Astrophysics Data System (ADS)

Kelly, Bryce F. J.; Iverach, Charlotte P.; Ginty, Elisa; Bashir, Safdar; Lowry, Dave; Fisher, Rebecca E.; France, James L.; Nisbet, Euan G.

2017-04-01

Bottom-up global methane emission estimates are important for guiding policy development and mitigation strategies. Such inventories enable rapid and consistent proportioning of emissions by industrial sectors and land use at various scales from city to country to global. There has been limited use of top-down measurements to guide refining emission inventories. Here we compare the EDGAR gridmap data version 4.2 with over 5000 km of daytime ground level mobile atmospheric methane surveys in eastern Australia. The landscapes and industries surveyed include: urban environments, dryland farming, intensive livestock farming (both beef and lamb), irrigation agriculture, open cut and underground coal mining, and coal seam gas production. Daytime mobile methane surveys over a 2-year period show that at the landscape scale there is a high level of repeatability for the mole fraction of methane measured in the ground level atmosphere. Such consistency in the mole fraction of methane indicates that these data can be used as a proxy for flux. A scatter plot of the EDGAR emission gridmap Log[ton substance / 0.1 degree x 0.1 degree / year] versus the median mole fraction of methane / 0.1 degree x 0.1 degree in the ground level atmosphere highlights that the extent of elevated methane emissions associated with coal mining in the Hunter coalfields, which covers an area of 56 km by 24 km, has been under-represented in the EDGAR input data. Our results also show that methane emissions from country towns (population < 100,000) are underestimated in the EDGAR inventory. This is possibly due to poor information on the extent of urban gas leaks. Given the uncertainties associated with the base land use and industry data for each country, we generalise the Australian observations to the global inventory with caution. The extensive comparison of top-down measurements versus the EDGAR version 4.2 methane gridmaps highlights the need for adjustments to the base resource data and/or the emission factors applied for coal mining, especially emissions from underground-mine venting. Also, more detail is required on the areal extent and rate of leakage from the gas distribution systems. This is likely to be the case for many other countries. Our results highlight the value of mobile methane surveys for guiding the refinement of bottom-up emission estimates, and they also suggest the expansion of all forms of top-down emission estimates would result in reduced uncertainty in the global methane budget.

Advanced CO 2 Leakage Mitigation using Engineered Biomineralization Sealing Technologies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spangler, Lee; Cunningham, Alfred; Phillips, Adrienne

2015-03-31

This research project addresses one of the goals of the DOE Carbon Sequestration Program (CSP). The CSP core R&D effort is driven by technology and is accomplished through laboratory and pilot scale research aimed at new technologies for greenhouse gas mitigation. Accordingly, this project was directed at developing novel technologies for mitigating unwanted upward leakage of carbon dioxide (CO 2) injected into the subsurface as part of carbon capture and storage (CCS) activities. The technology developed by way of this research project is referred to as microbially induced calcite precipitation (MICP).

Impact of Methane Leak Detection and Repair Programs: Determining Pre- and Post-Survey Emissions Profiles

NASA Astrophysics Data System (ADS)

Roda-Stuart, D. J.; Ravikumar, A. P.; Brandt, A. R.

2017-12-01

Upstream production sites contribute 66 percent of methane emissions from natural gas systems [1]. Being a major greenhouse gas, many states and national governments are developing policies to reduce methane emissions. Recent policies to address this issue have focused on periodic leak detection and repair (LDAR) surveys at oil and gas facilities [2]. Development of effective LDAR surveys is complicated by two things. First, available empirical data makes it difficult to say anything definitive about which facilities or equipment are most prone to leakage. Second, there has been little research done on post-LDAR emissions profiles and the time evolution of leaks, two measures that would influence survey effectiveness and cost. In this work, we present data from LDAR operations conducted at upstream facilities of a Canadian natural gas producer. Surveys were done by an outside contractor using a FLIR optical gas imaging camera. Twenty-two well pads, five processing plants, and three compressor stations were surveyed, of which four, two, and one, respectively, were revisited. We examine the persistence of leaks over time periods ranging from 6 months to 15 months following the initial LDAR survey. Developing pre- and post-survey emission factors and distributions can help inform survey schedules and help update and monitor mitigation targets. Furthermore, we analyze the effect of weather conditions, survey frequency, and operational characteristics of equipment on the effectiveness of the LDAR program. For instance, we find that a survey done at the commissioning of a gas processing plant yields both safety and emissions reduction benefits. Using leak frequency distributions, we identify components and equipment that require more frequent and targeted surveying. Insights from this study can assist businesses and policy makers develop methane mitigation policies aimed at maximizing the marginal benefits of LDAR programs. [1] Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2015. US Environmental Protection Agency, 2017. [2] New Source Performance Standards; Oil and Natural Gas Sector: Emission Standards for New, Reconstructed, and Modified Sources. Federal Register, 81(107):35824-35942, 2016.

Emissions from residential combustion considering end-uses and spatial constraints: Part II, emission reduction scenarios

NASA Astrophysics Data System (ADS)

Winijkul, Ekbordin; Bond, Tami C.

2016-01-01

Cooking, heating, and other activities in the residential sector are major sources of indoor and outdoor air pollution, especially when solid fuels are used to provide energy. Because of their deleterious effects on the atmosphere and human health, multinational strategies to reduce emissions have been proposed. This study examines the effects of some possible policies, considering realistic factors that constrain mitigation: end-uses, spatial constraints involving proximity to forest or electricity, existing technology, and assumptions about user behavior. Reduction scenarios are applied to a year-2010, spatially distributed baseline of emissions of particulate matter, black carbon, organic carbon, nitrogen oxides, methane, non-methane hydrocarbons, carbon monoxide, and carbon dioxide. Scenarios explored are: (1) cleanest current stove, where we assume that existing technology in each land type is applied to burn existing fuels; (2) stove standards, where we assume that stoves are designed to meet performance standards; and (3) clean fuels, where users adopt the cleanest fuels plausible in each land type. We assume that people living in forest access areas continue to use wood regardless of available fuels, so the clean-fuels scenario leads to a reduction in emissions of 18-25%, depending on the pollutant, across the study region. Cleaner stoves preferentially affect land types with forest access, where about half of the fuel is used; emission reductions range from 25 to 82%, depending on the pollutant. If stove performance standards can be met, particulate matter emissions are reduced by 62% for the loosest standards and 95% for the tightest standards, and carbon monoxide is reduced by 40% and 62% for the loosest and tightest standards. Reductions in specific regions and countries depend on the existing fuel mixture and the population division among land types, and are explored for Latin America, Africa, East Asia, South Asia, and Southeast Asia.

Airborne vs. Inventory Measurements of Methane Emissions in the Alberta Upstream Oil and Gas Sector

NASA Astrophysics Data System (ADS)

Johnson, M.; Tyner, D. R.; Conley, S.; Schwietzke, S.; Zavala Araiza, D.

2017-12-01

Airborne measurements of methane emission rates were directly compared with detailed, spatially-resolved inventory estimates for different oil and gas production regions in Alberta, Canada. For a 50 km × 50 km region near Red Deer, Alberta, containing 2700 older gas and oil wells, measured methane emissions were 16 times higher than reported venting and flaring volumes would suggest, but consistent with regional inventory estimates (which include estimates for additional emissions from pneumatic equipment, fugitive leaks, gas migration, etc.). This result highlights how 94% of methane emissions in this region are attributable to sources missing from current reporting requirements. The comparison was even more stark for a 60 km × 60 km region near Lloydminster, dominated by 2300 cold heavy oil with sand (CHOPS) production sites. Aircraft measured methane emissions in this region were 5 times larger than that expected from reported venting and flaring volumes, and more than 3 times greater than regional inventory estimates. This significant discrepancy is most likely attributable to underreported intentional venting of casing gas at CHOPS sites, which is generally estimated based on the product of the measured produced oil volume and an assumed gas to oil ratio (GOR). GOR values at CHOPS sites can be difficult to measure and can be notoriously variable in time. Considering the implications for other CHOPS sites across Alberta only, the present results suggest that total reported venting in Alberta is low by a factor of 2.4 (range of 2.0-2.7) and total methane emissions from the conventional oil and gas sector (excluding mined oil sands) are likely at least 25-41% greater than currently estimated. This work reveals critical gaps in current measurement and reporting, while strongly supporting the need for urgent mitigation efforts in the context of newly proposed federal methane regulations in Canada, and separate regulatory development efforts in the province of Alberta.

Design and Use of a Full Flow Sampling System (FFS) for the Quantification of Methane Emissions

PubMed Central

Johnson, Derek R.; Covington, April N.; Clark, Nigel N.

2016-01-01

The use of natural gas continues to grow with increased discovery and production of unconventional shale resources. At the same time, the natural gas industry faces continued scrutiny for methane emissions from across the supply chain, due to methane's relatively high global warming potential (25-84x that of carbon dioxide, according to the Energy Information Administration). Currently, a variety of techniques of varied uncertainties exists to measure or estimate methane emissions from components or facilities. Currently, only one commercial system is available for quantification of component level emissions and recent reports have highlighted its weaknesses. In order to improve accuracy and increase measurement flexibility, we have designed, developed, and implemented a novel full flow sampling system (FFS) for quantification of methane emissions and greenhouse gases based on transportation emissions measurement principles. The FFS is a modular system that consists of an explosive-proof blower(s), mass airflow sensor(s) (MAF), thermocouple, sample probe, constant volume sampling pump, laser based greenhouse gas sensor, data acquisition device, and analysis software. Dependent upon the blower and hose configuration employed, the current FFS is able to achieve a flow rate ranging from 40 to 1,500 standard cubic feet per minute (SCFM). Utilization of laser-based sensors mitigates interference from higher hydrocarbons (C2+). Co-measurement of water vapor allows for humidity correction. The system is portable, with multiple configurations for a variety of applications ranging from being carried by a person to being mounted in a hand drawn cart, on-road vehicle bed, or from the bed of utility terrain vehicles (UTVs). The FFS is able to quantify methane emission rates with a relative uncertainty of ± 4.4%. The FFS has proven, real world operation for the quantification of methane emissions occurring in conventional and remote facilities. PMID:27341646

Design and Use of a Full Flow Sampling System (FFS) for the Quantification of Methane Emissions.

PubMed

Johnson, Derek R; Covington, April N; Clark, Nigel N

2016-06-12

The use of natural gas continues to grow with increased discovery and production of unconventional shale resources. At the same time, the natural gas industry faces continued scrutiny for methane emissions from across the supply chain, due to methane's relatively high global warming potential (25-84x that of carbon dioxide, according to the Energy Information Administration). Currently, a variety of techniques of varied uncertainties exists to measure or estimate methane emissions from components or facilities. Currently, only one commercial system is available for quantification of component level emissions and recent reports have highlighted its weaknesses. In order to improve accuracy and increase measurement flexibility, we have designed, developed, and implemented a novel full flow sampling system (FFS) for quantification of methane emissions and greenhouse gases based on transportation emissions measurement principles. The FFS is a modular system that consists of an explosive-proof blower(s), mass airflow sensor(s) (MAF), thermocouple, sample probe, constant volume sampling pump, laser based greenhouse gas sensor, data acquisition device, and analysis software. Dependent upon the blower and hose configuration employed, the current FFS is able to achieve a flow rate ranging from 40 to 1,500 standard cubic feet per minute (SCFM). Utilization of laser-based sensors mitigates interference from higher hydrocarbons (C2+). Co-measurement of water vapor allows for humidity correction. The system is portable, with multiple configurations for a variety of applications ranging from being carried by a person to being mounted in a hand drawn cart, on-road vehicle bed, or from the bed of utility terrain vehicles (UTVs). The FFS is able to quantify methane emission rates with a relative uncertainty of ± 4.4%. The FFS has proven, real world operation for the quantification of methane emissions occurring in conventional and remote facilities.

Continuous time-resolved regional methane leak detection with on-line background estimation using a novel combination of dual frequency comb laser spectroscopy and atmospheric inversions

NASA Astrophysics Data System (ADS)

Alden, C. B.; Coburn, S.; Wright, R.; Baumann, E.; Cossel, K.; Sweeney, C.; Ghosh, S.; Newbury, N.; Prasad, K.; Coddington, I.; Rieker, G. B.

2017-12-01

Advances in natural gas extraction technology have led to increased US production and transport activity, and as a consequence, an increased need for monitoring of methane leaks. Current leak detection methods provide time snapshots, and not continuous, time-varying estimates of emissions. Most approaches also require specific atmospheric conditions, operators, or the use of a tracer gas, requiring site access. Given known intermittency in fugitive methane emissions, continuous monitoring is a critical need for emissions mitigation. We present a novel leak detection method that employs dual frequency comb spectrometry to offer continuous, autonomous, leak detection and quantification over square-km scale areas. The spectrometer is situated in a field of natural gas pads, and a series of retroreflectors around the field direct light back to a detector. The laser light spans 1620-1680 nm with 0.002 nm line spacing, measuring thousands of individual absorption features from multiple species. The result is high-stability trace gas (here CH4, CO2, and H2O) measurements over long (1 km+) open paths through the atmosphere. Measurements are used in an atmospheric inversion to estimate the time variability of emissions at each location of interest. Importantly, the measurement framework and inversion solve explicitly for background concentrations, which vary rapidly in fields of active oil and gas production. We present the results of controlled-leak field tests in rural Colorado. We demonstrate the ability to locate and size a leak located 1 km away from the spectrometer and varying in strength from 1.5 to 7.7 g/min, resulting in mean atmospheric enhancements of 20 ppb. The inversion correctly identifies when the leak turned on and off over a 24-hour period, and determines the mean leak strength to within 10% of the true controlled rate. We further demonstrate the ability of the system to correctly locate and size the start and end of simultaneous 2.7 to 4.8 g/min leaks from 2 sources in a field of 5 potential leak locations. Finally, we present the results of leak-detection tests in active oil and gas fields in the Denver Julesburg Basin, where background methane is complex.

ENGINEERING AND ECONOMIC EVALUATION OF GAS RECOVERY AND UTILIZATION TECHNOLOGIES AT SELECTED U.S. MINES

EPA Science Inventory

Methane liberated in underground coal mines is a severe safety hazard to miners. It is also a major contributor to the build-up of greenhouse gases in the global atmosphere. This report presents an engineering and economic evaluation of several methane recovery and end-use techno...

Heterogeneous Nucleation of Methane Hydrate in a Water-Decane-Methane Emulsion

NASA Astrophysics Data System (ADS)

Shestakov, V. A.; Kosyakov, V. I.; Manakov, A. Yu.; Stoporev, A. S.; Grachev, E. V.

2018-07-01

Heterogeneous nucleation in disperse systems with metastable disperse phases plays an important role in the mechanisms of environmental and technological processes. The effect the concentration and activity of particles that initiate the formation of a new phase have on nucleation processes in such systems is considered. An approach is proposed that allows construction of a spectrum of particle activity characterizing the features of nucleation in a sample, based on the fraction of crystallized droplets depending on the level of supercooling and the use of Weibull's distribution. The proposed method is used to describe experimental data on the heterogeneous nucleation of methane hydrate in an emulsion in a water-decane-methane system.

Life cycle assessment of four municipal solid waste management scenarios in China

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hong Jinglan, E-mail: hongjing@sdu.edu.c; Li Xiangzhi; Zhaojie Cui

2010-11-15

A life cycle assessment was carried out to estimate the environmental impact of municipal solid waste. Four scenarios mostly used in China were compared to assess the influence of various technologies on environment: (1) landfill, (2) incineration, (3) composting plus landfill, and (4) composting plus incineration. In all scenarios, the technologies significantly contribute to global warming and increase the adverse impact of non-carcinogens on the environment. The technologies played only a small role in the impact of carcinogens, respiratory inorganics, terrestrial ecotoxicity, and non-renewable energy. Similarly, the influence of the technologies on the way other elements affect the environment wasmore » ignorable. Specifically, the direct emissions from the operation processes involved played an important role in most scenarios except for incineration, while potential impact generated from transport, infrastructure and energy consumption were quite small. In addition, in the global warming category, highest potential impact was observed in landfill because of the direct methane gas emissions. Electricity recovery from methane gas was the key factor for reducing the potential impact of global warming. Therefore, increasing the use of methane gas to recover electricity is highly recommended to reduce the adverse impact of landfills on the environment.« less

Commercialization of Immobilized Amino-Siliane/Amine or Biochar Sorbents for the Capture of Carbon Dioxide from Various Methane Gas Streams. Abstract - Cooperative Research and Development Agreement between BioEnergy Development, LLC and National Energy Technology Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gray, McMahan L.; Shipley, Greg

Currently, landfill gases are flared-off, which creates carbon dioxide (CO 2) and particulate matter air emissions, while still containing small amounts of unburned methane (CH 4). All of these pollutants contribute to environmental health hazards and global climate change. The same is true with industrial processes that use thermal technologies to process biomass, as these also generate the pollutant gases and particulates. In conjunction with BioEnegy Development (BED), NETL researchers will adapt the Basic Immobilized Amine Sorbent (BIAS) material technology for use in BED’s biorefineries. The goal of this proposed work is to develop NETL’s immobilized hydrophobic amino-silane/amine pellets inmore » combination with BED’s biochar materials (derived from the pyrolysis of biomass) into a commercially-accepted means of capturing/recovering CH 4 and CO 2 gases from landfills. Overall, the NETL-BioEnergy Development partnership will focus on the development and application of this carbon management sorbent technology to commercial carbon capture processes and promotion of clean methane based fuel streams.« less

Assessment of Methane Emissions – Impact of Using Natural Gas Engines in Unconventional Resource Development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nix, Andrew; Johnson, Derek; Heltzel, Robert

Researchers at the Center for Alternative Fuels, Engines, and Emissions (CAFEE) completed a multi-year program under DE-FE0013689 entitled, “Assessing Fugitive Methane Emissions Impact Using Natural Gas Engines in Unconventional Resource Development.” When drilling activity was high and industry sought to lower operating costs and reduce emissions they began investing in dual fuel and dedicated natural gas engines to power unconventional well equipment. From a review of literature we determined that the prime-movers (or major fuel consumers) of unconventional well development were the service trucks (trucking), horizontal drilling rig (drilling) engines, and hydraulic stimulation pump (fracturing) engines. Based on early findingsmore » from on-road studies we assessed that conversion of prime movers to operate on natural gas could contribute to methane emissions associated with unconventional wells. As such, we collected significant in-use activity data from service trucks and in-use activity, fuel consumption, and gaseous emissions data from drilling and fracturing engines. Our findings confirmed that conversion of the prime movers to operate as dual fuel or dedicated natural gas – created an additional source of methane emissions. While some gaseous emissions were decreased from implementation of these technologies – methane and CO 2 equivalent emissions tended to increase, especially for non-road engines. The increases were highest for dual fuel engines due to methane slip from the exhaust and engine crankcase. Dedicated natural gas engines tended to have lower exhaust methane emissions but higher CO 2 emissions due to lower efficiency. Therefore, investing in currently available natural gas technologies for prime movers will increase the greenhouse gas footprint of the unconventional well development industry.« less

GREENHOUSE GAS (GHG) MITIGATION AND MONITORING TECHNOLOGY PERFORMANCE: ACTIVITIES OF THE GHG TECHNOLOGY VERIFICATION CENTER

EPA Science Inventory

The paper discusses greenhouse gas (GHG) mitigation and monitoring technology performance activities of the GHG Technology Verification Center. The Center is a public/private partnership between Southern Research Institute and the U.S. EPA's Office of Research and Development. It...

Testing a biofilter cover design to mitigate dairy effluent pond methane emissions.

PubMed

Pratt, Chris; Deslippe, Julie; Tate, Kevin R

2013-01-02

Biofiltration, whereby CH(4) is oxidized by methanotrophic bacteria, is a potentially effective strategy for mitigating CH(4) emissions from anaerobic dairy effluent lagoons/ponds, which typically produce insufficient biogas for energy recovery. This study reports on the effectiveness of a biofilter cover design at oxidizing CH(4) produced by dairy effluent ponds. Three substrates, a volcanic pumice soil, a garden-waste compost, and a mixture of the two, were tested as media for the biofilters. All substrates were suspended as 5 cm covers overlying simulated dairy effluent ponds. Methane fluxes supplied to the filters were commensurate with emission rates from typical dairy effluent ponds. All substrates oxidized more than 95% of the CH(4) influx (13.9 g CH(4) m(-3) h(-1)) after two months and continued to display high oxidation rates for the remaining one month of the trial. The volcanic soil biofilters exhibited the highest oxidation rates (99% removal). When the influx CH(4) dose was doubled for a month, CH(4) removal rates remained >90% for all substrates (maximum = 98%, for the volcanic soil), suggesting that biofilters have a high capacity to respond to increases in CH(4) loads. Nitrous oxide emissions from the biofilters were negligible (maximum = 19.9 mg N(2)O m(-3) h(-1)) compared with CH(4) oxidation rates, particularly from the volcanic soil that had a much lower microbial-N (75 mg kg(-1)) content than the compost-based filters (>240 mg kg(-1)). The high and sustained CH(4) oxidation rates observed in this laboratory study indicate that a biofilter cover design is a potentially efficient method to mitigate CH(4) emissions from dairy effluent ponds. The design should now be tested under field conditions.

Degraded Land Restoration in Reinstating CH4 Sink

PubMed Central

Singh, Jay Shankar; Gupta, Vijai K.

2016-01-01

Methane (CH4), a potent greenhouse gas, contributes about one third to the global green house gas emissions. CH4-assimilating microbes (mostly methanotrophs) in upland soils play very crucial role in mitigating the CH4 release into the atmosphere. Agricultural, environmental, and climatic shifts can alter CH4 sink profiles of soils, likely through shifts in CH4-assimilating microbial community structure and function. Landuse change, as forest and grassland ecosystems altered to agro-ecosystems, has already attenuated the soil CH4 sink potential, and are expected to be continued in the future. We hypothesized that variations in CH4 uptake rates in soils under different landuse practices could be an indicative of alterations in the abundance and/or type of methanotrophic communities in such soils. However, only a few studies have addressed to number and methanotrophs diversity and their correlation with the CH4 sink potential in soils of rehabilitated/restored lands. We focus on landuse practices that can potentially mitigate CH4 gas emissions, the most prominent of which are improved cropland, grazing land management, use of bio-fertilizers, and restoration of degraded lands. In this perspective paper, it is proposed that restoration of degraded lands can contribute considerably to improved soil CH4 sink strength by retrieving/conserving abundance and assortment of efficient methanotrophic communities. We believe that this report can assist in identifying future experimental directions to the relationships between landuse changes, methane-assimilating microbial communities and soil CH4 sinks. The exploitation of microbial communities other than methanotrophs can contribute significantly to the global CH4 sink potential and can add value in mitigating the CH4 problems. PMID:27379053

Degraded Land Restoration in Reinstating CH4 Sink.

PubMed

Singh, Jay Shankar; Gupta, Vijai K

2016-01-01

Methane (CH4), a potent greenhouse gas, contributes about one third to the global green house gas emissions. CH4-assimilating microbes (mostly methanotrophs) in upland soils play very crucial role in mitigating the CH4 release into the atmosphere. Agricultural, environmental, and climatic shifts can alter CH4 sink profiles of soils, likely through shifts in CH4-assimilating microbial community structure and function. Landuse change, as forest and grassland ecosystems altered to agro-ecosystems, has already attenuated the soil CH4 sink potential, and are expected to be continued in the future. We hypothesized that variations in CH4 uptake rates in soils under different landuse practices could be an indicative of alterations in the abundance and/or type of methanotrophic communities in such soils. However, only a few studies have addressed to number and methanotrophs diversity and their correlation with the CH4 sink potential in soils of rehabilitated/restored lands. We focus on landuse practices that can potentially mitigate CH4 gas emissions, the most prominent of which are improved cropland, grazing land management, use of bio-fertilizers, and restoration of degraded lands. In this perspective paper, it is proposed that restoration of degraded lands can contribute considerably to improved soil CH4 sink strength by retrieving/conserving abundance and assortment of efficient methanotrophic communities. We believe that this report can assist in identifying future experimental directions to the relationships between landuse changes, methane-assimilating microbial communities and soil CH4 sinks. The exploitation of microbial communities other than methanotrophs can contribute significantly to the global CH4 sink potential and can add value in mitigating the CH4 problems.

Emerging role of wetland methane emissions in driving 21st century climate change.

PubMed

Zhang, Zhen; Zimmermann, Niklaus E; Stenke, Andrea; Li, Xin; Hodson, Elke L; Zhu, Gaofeng; Huang, Chunlin; Poulter, Benjamin

2017-09-05

Wetland methane (CH 4 ) emissions are the largest natural source in the global CH 4 budget, contributing to roughly one third of total natural and anthropogenic emissions. As the second most important anthropogenic greenhouse gas in the atmosphere after CO 2 , CH 4 is strongly associated with climate feedbacks. However, due to the paucity of data, wetland CH 4 feedbacks were not fully assessed in the Intergovernmental Panel on Climate Change Fifth Assessment Report. The degree to which future expansion of wetlands and CH 4 emissions will evolve and consequently drive climate feedbacks is thus a question of major concern. Here we present an ensemble estimate of wetland CH 4 emissions driven by 38 general circulation models for the 21st century. We find that climate change-induced increases in boreal wetland extent and temperature-driven increases in tropical CH 4 emissions will dominate anthropogenic CH 4 emissions by 38 to 56% toward the end of the 21st century under the Representative Concentration Pathway (RCP2.6). Depending on scenarios, wetland CH 4 feedbacks translate to an increase in additional global mean radiative forcing of 0.04 W·m -2 to 0.19 W·m -2 by the end of the 21st century. Under the "worst-case" RCP8.5 scenario, with no climate mitigation, boreal CH 4 emissions are enhanced by 18.05 Tg to 41.69 Tg, due to thawing of inundated areas during the cold season (December to May) and rising temperature, while tropical CH 4 emissions accelerate with a total increment of 48.36 Tg to 87.37 Tg by 2099. Our results suggest that climate mitigation policies must consider mitigation of wetland CH 4 feedbacks to maintain average global warming below 2 °C.

Emerging role of wetland methane emissions in driving 21st century climate change

PubMed Central

Zimmermann, Niklaus E.; Stenke, Andrea; Li, Xin; Hodson, Elke L.; Zhu, Gaofeng; Huang, Chunlin; Poulter, Benjamin

2017-01-01

Wetland methane (CH4) emissions are the largest natural source in the global CH4 budget, contributing to roughly one third of total natural and anthropogenic emissions. As the second most important anthropogenic greenhouse gas in the atmosphere after CO2, CH4 is strongly associated with climate feedbacks. However, due to the paucity of data, wetland CH4 feedbacks were not fully assessed in the Intergovernmental Panel on Climate Change Fifth Assessment Report. The degree to which future expansion of wetlands and CH4 emissions will evolve and consequently drive climate feedbacks is thus a question of major concern. Here we present an ensemble estimate of wetland CH4 emissions driven by 38 general circulation models for the 21st century. We find that climate change-induced increases in boreal wetland extent and temperature-driven increases in tropical CH4 emissions will dominate anthropogenic CH4 emissions by 38 to 56% toward the end of the 21st century under the Representative Concentration Pathway (RCP2.6). Depending on scenarios, wetland CH4 feedbacks translate to an increase in additional global mean radiative forcing of 0.04 W·m−2 to 0.19 W·m−2 by the end of the 21st century. Under the “worst-case” RCP8.5 scenario, with no climate mitigation, boreal CH4 emissions are enhanced by 18.05 Tg to 41.69 Tg, due to thawing of inundated areas during the cold season (December to May) and rising temperature, while tropical CH4 emissions accelerate with a total increment of 48.36 Tg to 87.37 Tg by 2099. Our results suggest that climate mitigation policies must consider mitigation of wetland CH4 feedbacks to maintain average global warming below 2 °C. PMID:28827347

Hazard mitigation in coal mines

NASA Astrophysics Data System (ADS)

Rashmi, R. V.; Devalal, Shilpa; Jacob, Anjali; Vidhyapathi, C. M.

2017-11-01

Today’s world witnesses increased number of mine accidents caused due to explosion and fire. When the methane gas concentration goes high, it causes fire leading to explosion. In this paper, an IoT based system is proposed to ensure safety to the mine workers in underground collieries. The proposed system consists of DHT-11 sensor to monitor the temperature and humidity of coal mines. When the gas sensor detects high methane gas level, blower is activated so that the atmospheric air can be pumped in from outside to dilute the gas concentration. The smoke sensor is also used to detect the fire. In case of any abnormality in any of these parameters the buzzer sounds. All these parameters are uploaded to the cloud directly so that the people at the control station can be well informed of the underground mines.

Potential of tannin-rich plants for modulating ruminal microbes and ruminal fermentation in sheep.

PubMed

Rira, M; Morgavi, D P; Archimède, H; Marie-Magdeleine, C; Popova, M; Bousseboua, H; Doreau, M

2015-01-01

The objective of this work was to study nutritional strategies for decreasing methane production by ruminants fed tropical diets, combining in vitro and in vivo methods. The in vitro approach was used to evaluate the dose effect of condensed tannins (CT) contained in leaves of Gliricidia sepium, Leucaena leucocephala, and Manihot esculenta (39, 75, and 92 g CT/kg DM, respectively) on methane production and ruminal fermentation characteristics. Tannin-rich plants (TRP) were incubated for 24 h alone or mixed with a natural grassland hay based on Dichanthium spp. (control plant), so that proportions of TRP were 0, 0.25, 0.5, 0.75, and 1.0. Methane production, VFA concentration, and fermented OM decreased with increased proportions of TRP. Numerical differences on methane production and VFA concentration among TRP sources may be due to differences in their CT content, with greater effects for L. leucocephala and M. esculenta than for G. sepium. Independently of TRP, the response to increasing doses of CT was linear for methane production but quadratic for VFA concentration. As a result, at moderate tannin dose, methane decreased more than VFA. The in vivo trial was conducted to investigate the effect of TRP on different ruminal microbial populations. To this end, 8 rumen-cannulated sheep from 2 breeds (Texel and Blackbelly) were used in two 4 × 4 Latin square designs. Diets were fed ad libitum and were composed of the same feeds used for the in vitro trial: control plant alone or combined with pellets made from TRP leaves at 44% of the diet DM. Compared to TRP, concentration of Ruminococcus flavefaciens was greater for the control diet and concentration of Ruminococcus albus was least for the control diet. The methanogen population was greater for Texel than for Blackbelly. By contrast, TRP-containing diets did not affect protozoa or Fibrobacter succinogenes numbers. Hence, TRP showed potential for mitigating methane production by ruminants. These findings suggest that TRP fed as pellets could be used to decrease methane production.

Source Attribution of Methane Emissions in Northeastern Colorado Using Ammonia to Methane Emission Ratios

NASA Astrophysics Data System (ADS)

Eilerman, S. J.; Neuman, J. A.; Peischl, J.; Aikin, K. C.; Ryerson, T. B.; Perring, A. E.; Robinson, E. S.; Holloway, M.; Trainer, M.

2015-12-01

Due to recent advances in extraction technology, oil and natural gas extraction and processing in the Denver-Julesburg basin has increased substantially in the past decade. Northeastern Colorado is also home to over 250 concentrated animal feeding operations (CAFOs), capable of hosting over 2 million head of ruminant livestock (cattle and sheep). Because of methane's high Global Warming Potential, quantification and attribution of methane emissions from oil and gas development and agricultural activity are important for guiding greenhouse gas emission policy. However, due to the co-location of these different sources, top-down measurements of methane are often unable to attribute emissions to a specific source or sector. In this work, we evaluate the ammonia:methane emission ratio directly downwind of CAFOs using a mobile laboratory. Several CAFOs were chosen for periodic study over a 12-month period to identify diurnal and seasonal variation in the emission ratio as well as differences due to livestock type. Using this knowledge of the agricultural ammonia:methane emission ratio, aircraft measurements of ammonia and methane over oil and gas basins in the western US during the Shale Oil and Natural Gas Nexus (SONGNEX) field campaign in March and April 2015 can be used for source attribution of methane emissions.

Dynamics of the microbial community during continuous methane fermentation in continuously stirred tank reactors.

PubMed

Tang, Yue-Qin; Shigematsu, Toru; Morimura, Shigeru; Kida, Kenji

2015-04-01

Methane fermentation is an attractive technology for the treatment of organic wastes and wastewaters. However, the process is difficult to control, and treatment rates and digestion efficiency require further optimization. Understanding the microbiology mechanisms of methane fermentation is of fundamental importance to improving this process. In this review, we summarize the dynamics of microbial communities in methane fermentation chemostats that are operated using completely stirred tank reactors (CSTRs). Each chemostat was supplied with one substrate as the sole carbon source. The substrates include acetate, propionate, butyrate, long-chain fatty acids, glycerol, protein, glucose, and starch. These carbon sources are general substrates and intermediates of methane fermentation. The factors that affect the structure of the microbial community are discussed. The carbon source, the final product, and the operation conditions appear to be the main factors that affect methane fermentation and determine the structure of the microbial community. Understanding the structure of the microbial community during methane fermentation will guide the design and operation of practical wastewater treatments. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

The theory-practice gap of black carbon mitigation technologies in rural China

NASA Astrophysics Data System (ADS)

Zhang, Weishi; Li, Aitong; Xu, Yuan; Liu, Junfeng

2018-02-01

Black carbon mitigation has received increasing attention for its potential contribution to both climate change mitigation and air pollution control. Although different bottom-up models concerned with unit mitigation costs of various technologies allow the assessment of alternative policies for optimized cost-effectiveness, the lack of adequate data often forced many reluctant explicit and implicit assumptions that deviate away from actual situations of rural residential energy consumption in developing countries, where most black carbon emissions occur. To gauge the theory-practice gap in black carbon mitigation - the unit cost differences that lie between what is estimated in the theory and what is practically achieved on the ground - this study conducted an extensive field survey and analysis of nine mitigation technologies in rural China, covering both northern and southern regions with different residential energy consumption patterns. With a special focus on two temporal characteristics of those technologies - lifetimes and annual utilization rates, this study quantitatively measured the unit cost gaps and explain the technical as well as sociopolitical mechanisms behind. Structural and behavioral barriers, which have affected the technologies' performance, are discussed together with policy implications to narrow those gaps.

Global assessment of technological innovation for climate change adaptation and mitigation in developing world.

PubMed

Adenle, Ademola A; Azadi, Hossein; Arbiol, Joseph

2015-09-15

Concerns about mitigating and adapting to climate change resulted in renewing the incentive for agricultural research investments and developing further innovation priorities around the world particularly in developing countries. In the near future, development of new agricultural measures and proper diffusion of technologies will greatly influence the ability of farmers in adaptation and mitigation to climate change. Using bibliometric approaches through output of academic journal publications and patent-based data, we assess the impact of research and development (R&D) for new and existing technologies within the context of climate change mitigation and adaptation. We show that many developing countries invest limited resources for R&D in relevant technologies that have great potential for mitigation and adaption in agricultural production. We also discuss constraints including weak infrastructure, limited research capacity, lack of credit facilities and technology transfer that may hinder the application of innovation in tackling the challenges of climate change. A range of policy measures is also suggested to overcome identified constraints and to ensure that potentials of innovation for climate change mitigation and adaptation are realized. Copyright © 2015 Elsevier Ltd. All rights reserved.

Technology summary of the in situ bioremediation demonstration (methane biostimulation) via horizontal wells at the Savannah River Site Integrated Demonstration Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hazen, T.C.; Looney, B.B.; Fliermans, C.B.

1994-06-01

The US Department of Energy, Office of Technology Development, has been sponsoring full-scale environmental restoration technology demonstrations for the past 4 years. The Savannah River Site Integrated Demonstration focuses on ``Clean-up of Soils ad Groundwater Contaminated with Chlorinated VOCs.`` Several laboratories including our own had demonstrated the ability of methanotrophic bacteria to completely degrade or mineralize chlorinated solvents, and these bacteria were naturally found in soil and aquifer material. Thus the test consisted of injection of methane mixed with air into the contaminated aquifer via a horizontal well and extraction from the vadose zone via a parallel horizontal well.

Oxidative mitigation of aquatic methane emissions in large Amazonian rivers.

PubMed

Sawakuchi, Henrique O; Bastviken, David; Sawakuchi, André O; Ward, Nicholas D; Borges, Clovis D; Tsai, Siu M; Richey, Jeffrey E; Ballester, Maria Victoria R; Krusche, Alex V

2016-03-01

The flux of methane (CH4 ) from inland waters to the atmosphere has a profound impact on global atmospheric greenhouse gas (GHG) levels, and yet, strikingly little is known about the dynamics controlling sources and sinks of CH4 in the aquatic setting. Here, we examine the cycling and flux of CH4 in six large rivers in the Amazon basin, including the Amazon River. Based on stable isotopic mass balances of CH4 , inputs and outputs to the water column were estimated. We determined that ecosystem methane oxidation (MOX) reduced the diffusive flux of CH4 by approximately 28-96% and varied depending on hydrologic regime and general geochemical characteristics of tributaries of the Amazon River. For example, the relative amount of MOX was maximal during high water in black and white water rivers and minimal in clear water rivers during low water. The abundance of genetic markers for methane-oxidizing bacteria (pmoA) was positively correlated with enhanced signals of oxidation, providing independent support for the detected MOX patterns. The results indicate that MOX in large Amazonian rivers can consume from 0.45 to 2.07 Tg CH4 yr(-1) , representing up to 7% of the estimated global soil sink. Nevertheless, climate change and changes in hydrology, for example, due to construction of dams, can alter this balance, influencing CH4 emissions to atmosphere. © 2015 John Wiley & Sons Ltd.

Vertical profiles of community abundance and diversity of anaerobic methanotrophic archaea (ANME) and bacteria in a simple waste landfill in north China.

PubMed

Dong, Jun; Ding, Linjie; Wang, Xu; Chi, Zifang; Lei, Jiansen

2015-03-01

Anaerobic methane oxidation (AMO) is considered to be an important sink of CH4 in habitats as marine sediments. But, few studies focused on AMO in landfills which may be an important sink of CH4 derived from waste fermentation. To show evidence of AMO and to uncover function anaerobic methanotroph (ANME) community in landfill, different age waste samples were collected in Jinqianpu landfill located in north China. Through high-throughput sequencing, Methanomicrobiales and Methanosarcinales archaea associated with ANME and reverse methanogenic archaea of Methanosarcina and Methanobacterium were detected. Sulfate-reducing bacteria (SRB) (Desulfobulbus and Desulfococcus) which could couple with ANME-conducting AMO were also found. But, the community structure of ANME had no significant difference with depths. From the results of investigation, we can come to a conclusion that sulfate-dependent anaerobic methane oxidation (SR-DAMO) would be the dominant AMO process in the landfill, while iron-dependent anaerobic methane oxidation (M/IR-DAMO) process was weak though concentration of ferric iron was large in the landfill. Denitrification-dependent anaerobic methane oxidation (NR-DAMO) was negative because of lack of nitrate and relevant function microorganisms in the landfill. Results also indicate that CH4 mitigation would have higher potential by increasing electron acceptor contents and promoting the growth of relevant function microorganisms.

The global methane budget 2000–2012

DOE PAGES

Saunois, Marielle; Bousquet, Philippe; Poulter, Ben; ...

2016-12-12

The global methane (CH 4) budget is becoming an increasingly important component for managing realistic pathways to mitigate climate change. This relevance, due to a shorter atmospheric lifetime and a stronger warming potential than carbon dioxide, is challenged by the still unexplained changes of atmospheric CH 4 over the past decade. Emissions and concentrations of CH 4 are continuing to increase, making CH 4 the second most important human-induced greenhouse gas after carbon dioxide. Two major difficulties in reducing uncertainties come from the large variety of diffusive CH 4 sources that overlap geographically, and from the destruction of CH 4more » by the very short-lived hydroxyl radical (OH). To address these difficulties, we have established a consortium of multi-disciplinary scientists under the umbrella of the Global Carbon Project to synthesize and stimulate research on the methane cycle, and producing regular (~biennial) updates of the global methane budget. This consortium includes atmospheric physicists and chemists, biogeochemists of surface and marine emissions, and socio-economists who study anthropogenic emissions. Following Kirschke et al. (2013), we propose here the first version of a living review paper that integrates results of top-down studies (exploiting atmospheric observations within an atmospheric inverse-modelling framework) and bottom-up models, inventories and data-driven approaches (including process-based models for estimating land surface emissions and atmospheric chemistry, and inventories for anthropogenic emissions, data-driven extrapolations).« less

The global methane budget 2000–2012

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saunois, Marielle; Bousquet, Philippe; Poulter, Ben

The global methane (CH 4) budget is becoming an increasingly important component for managing realistic pathways to mitigate climate change. This relevance, due to a shorter atmospheric lifetime and a stronger warming potential than carbon dioxide, is challenged by the still unexplained changes of atmospheric CH 4 over the past decade. Emissions and concentrations of CH 4 are continuing to increase, making CH 4 the second most important human-induced greenhouse gas after carbon dioxide. Two major difficulties in reducing uncertainties come from the large variety of diffusive CH 4 sources that overlap geographically, and from the destruction of CH 4more » by the very short-lived hydroxyl radical (OH). To address these difficulties, we have established a consortium of multi-disciplinary scientists under the umbrella of the Global Carbon Project to synthesize and stimulate research on the methane cycle, and producing regular (~biennial) updates of the global methane budget. This consortium includes atmospheric physicists and chemists, biogeochemists of surface and marine emissions, and socio-economists who study anthropogenic emissions. Following Kirschke et al. (2013), we propose here the first version of a living review paper that integrates results of top-down studies (exploiting atmospheric observations within an atmospheric inverse-modelling framework) and bottom-up models, inventories and data-driven approaches (including process-based models for estimating land surface emissions and atmospheric chemistry, and inventories for anthropogenic emissions, data-driven extrapolations).« less

15 CFR 971.604 - Best available technologies (BAT) and mitigation.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Best available technologies (BAT) and... Environmental Effects § 971.604 Best available technologies (BAT) and mitigation. (a) The Administrator shall..., the use of the best available technologies for the protection of safety, health, and the environment...

Sustainable biochar to mitigate global climate change

PubMed Central

Woolf, Dominic; Amonette, James E.; Street-Perrott, F. Alayne; Lehmann, Johannes; Joseph, Stephen

2010-01-01

Production of biochar (the carbon (C)-rich solid formed by pyrolysis of biomass) and its storage in soils have been suggested as a means of abating climate change by sequestering carbon, while simultaneously providing energy and increasing crop yields. Substantial uncertainties exist, however, regarding the impact, capacity and sustainability of biochar at the global level. In this paper we estimate the maximum sustainable technical potential of biochar to mitigate climate change. Annual net emissions of carbon dioxide (CO2), methane and nitrous oxide could be reduced by a maximum of 1.8 Pg CO2-C equivalent (CO2-Ce) per year (12% of current anthropogenic CO2-Ce emissions; 1 Pg=1 Gt), and total net emissions over the course of a century by 130 Pg CO2-Ce, without endangering food security, habitat or soil conservation. Biochar has a larger climate-change mitigation potential than combustion of the same sustainably procured biomass for bioenergy, except when fertile soils are amended while coal is the fuel being offset. PMID:20975722

NATIONAL ASSESSMENT OF ENVIRONMENTAL AND ECONOMIC BENEFITS FROM METHANE CONTROL AND UTILIZATION TECHNOLOGIES AT U.S. UNDERGROUND COAL MINES

EPA Science Inventory

The report gives results of EPA research into the emission processes and control strategies associated with underground coal mines in the U.S. (NOTE: Methane is a greenhouse gas in the atmosphere which ranks behind carbon dioxide as the second largest contributor to global warmin...

Energy and greenhouse gas life cycle assessment and cost analysis of aerobic and anaerobic membrane bioreactor systems: Influence of scale, population density, climate, and methane recovery.

PubMed

Cashman, Sarah; Ma, Xin; Mosley, Janet; Garland, Jay; Crone, Brian; Xue, Xiaobo

2018-04-01

This study calculated the energy and greenhouse gas life cycle and cost profiles of transitional aerobic membrane bioreactors (AeMBR) and anaerobic membrane bioreactors (AnMBR). Membrane bioreactors (MBR) represent a promising technology for decentralized wastewater treatment and can produce recycled water to displace potable water. Energy recovery is possible with methane generated from AnMBRs. Scenarios for these technologies were investigated for different scale systems serving various population densities under a number of climate conditions with multiple methane recovery options. When incorporating the displacement of drinking water, AeMBRs started to realize net energy benefits at the 1 million gallons per day (MGD) scale and mesophilic AnMBRs at the 5 MGD scale. For all scales, the psychrophilic AnMBR resulted in net energy benefits. This study provides insights into key performance characteristics needed before an informed decision can be made for a community to transition towards the adoption of MBR technologies. Copyright © 2018. Published by Elsevier Ltd.

Sustainable Mars Sample Return

NASA Technical Reports Server (NTRS)

Alston, Christie; Hancock, Sean; Laub, Joshua; Perry, Christopher; Ash, Robert

2011-01-01

The proposed Mars sample return mission will be completed using natural Martian resources for the majority of its operations. The system uses the following technologies: In-Situ Propellant Production (ISPP), a methane-oxygen propelled Mars Ascent Vehicle (MAV), a carbon dioxide powered hopper, and a hydrogen fueled balloon system (large balloons and small weather balloons). The ISPP system will produce the hydrogen, methane, and oxygen using a Sabatier reactor. a water electrolysis cell, water extracted from the Martian surface, and carbon dioxide extracted from the Martian atmosphere. Indigenous hydrogen will fuel the balloon systems and locally-derived methane and oxygen will fuel the MAV for the return of a 50 kg sample to Earth. The ISPP system will have a production cycle of 800 days and the estimated overall mission length is 1355 days from Earth departure to return to low Earth orbit. Combining these advanced technologies will enable the proposed sample return mission to be executed with reduced initial launch mass and thus be more cost efficient. The successful completion of this mission will serve as the next step in the advancement of Mars exploration technology.

Constructive Activation of Reservoir-Resident Microbes for Enhanced Oil Recovery

NASA Astrophysics Data System (ADS)

DeBruyn, R. P.

2017-12-01

Microbial communities living in subsurface oil reservoirs biodegrade oil, producing methane. If this process could create methane within the waterflooded pore spaces of an oilfield, the methane would be expected to remain and occupy pore space, decreasing water relative permeability, diverting water flow, and increasing oil recovery by expanding the swept zone of the waterflood. This approach was tested in an oilfield in northern Montana. Preliminary assessments were made of geochemical conditions and microbiological habitations. Then, a formulation of microbial activators, with composition tailored for the reservoir's conditions, was metered at low rates into the existing injection water system for one year. In the field, the responses observed included improved oil production performance; a slight increase in injection pressure; and increased time needed for tracers to move between injection and producing wells. We interpret these results to confirm that successful stimulation of the microbial community caused more methane to be created within the swept zone of the waterflooded reservoir. When the methane exsolved as water flowed between high-pressure injection and low-pressure production wells, the bubbles occupied pore space, reducing water saturation and relative permeability, and re-directing some water flow to "slower" unswept rock with lower permeability and higher oil saturation. In total, the waterflood's swept zone had been expanded to include previously-unflooded rock. This technology was applied in this field after screening based on careful anaerobic sampling, advanced microbiological analysis, and the ongoing success of its waterflood. No reservoir or geological or geophysical simulation models were employed, and physical modifications to field facilities were minor. This technology of utilizing existing microbial populations for enhanced oil recovery can therefore be considered for deployment into waterfloods where small scale, advanced maturity, or insufficiency of data make other technologies too expensive.

Biogas Technology on Supporting “Sustainable” Coffee Farmers in North Sumatera Province, Indonesia

NASA Astrophysics Data System (ADS)

Ginting, N.

2017-03-01

A study has been conducted in an area of coffee plantation in Samosir District, North Sumatera Province. The study was conducted in August until September 2016. The objective of this study is to investigate the benefits of using biogas technology in supporting coffee farmers’ productivity to be sustainable, i.e. methane as energy source for coffee roasting proceed instead of fired wood and slurry as organic fertilizer. Coffee cherry causes environmental problem when it is dumped openly, hence it is used to mix with buffalo feces in biodigesters to produce methane and organic fertilizer. Five biodigesters were used with 5 differents designs of composition: T1) 100% buffalo feces, T2) 75% buffalo feces + 25% coffee cherry, T3) 50% buffalo feces + 50% coffee cherry, T4) 25% buffalo feces + 75% coffee cherry, and T5) 100% coffee cherry. The key parameters measured were methane production and slurry chemical compositions including NPK, pH, and C/N. It is found that designs T1 and T2 were superior in methane production, and about 400 liters of methane were used in roasting 3 kg coffee bean as opposed to 6,6 kg fired wood. Designs T1 and T2 were also better in slurry chemical compositions than the other 3 designs. It is recommeded that local coffee farmers utilize coffee cherry based biogas technology in order for their productivity to be sustainable. It is noteworthy that this study is continued with the next one in which the resulting slurries are implemented to foster the growth of the coffee plants during the period of October until December 2016.

Mapping the isotopic signature of methane in South-Eastern Spain: complementing biogeochemical long-term research with short term observations

NASA Astrophysics Data System (ADS)

Àgueda, Alba; Morguí, Josep Anton; Vazquez Garcia, Eusebi; Curcoll, Roger; Lowry, David; Fisher, Rebecca E.; Nisbet, Euan G.

2016-04-01

As a greenhouse gas, methane has a global warming potential of 25 in a 100 year scale. In order to establish mitigation plans it is important to assess its sources and sinks which can be both of geological and biological origin. South-Eastern Spain is a region with many different possible methane sources: i) by seismic activity of many geological faults both inland and in the neighbouring marine region (i.e. the Carboneras fault crossing the Alborán Sea along Málaga coastline); ii) by seepage of methane from hydrates present in the marine regions close to the Gibraltar Strait and the Gulf of Cádiz; iii) by emissions from fossil fuels caused by high traffic of merchant ships and the presence of large harbours (Algeciras, Tetuan and Cádiz), and the Africa - Europe Gas Transport Network in the Gibraltar Strait region; iv) by organic matter decomposition in both highly productive marshlands and eutrophic reservoirs; v) by burning of agricultural debris for energy supply, mainly from olive residues. In this study, a methane mapping survey has been conducted in the area around three atmospheric stations of the ClimaDat Atmospheric Network for Continuous Measurements of Greenhouse Gases (www.climadat.es) located in South-Eastern Spain (Sierra de Grazalema (SGC3), Tarifa (EEC3) and Sierra de Segura (SSC3). A cavity ring down spectrometer (CRDS) (G2301m, Picarro®) installed on a car has been used to measure methane concentrations. Additionally, in selected points, air samples have been collected in Tedlar bags for isotopic signature analysis by CF-GC-IRMS (Continuous Flow Gas Chromatography-Isotope Ratio Mass Spectrometry). In order to obtain a map facilitating the identification of the different methane sources in the background air at regional scale, the mapping of isotopic signature of methane together with its concentration is a useful tool to obtain fast and direct information that will contribute to the knowledge of methane transport at the regional scale and will be helpful in the validation of transport models. *Corresponding author: Josep Anton Morguí - josep-anton.morgui@ic3.cat "The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) in the InGOS project under grant agreement n° 284274''

Model for estimating enteric methane emissions from United States dairy and feedlot cattle.

PubMed

Kebreab, E; Johnson, K A; Archibeque, S L; Pape, D; Wirth, T

2008-10-01

Methane production from enteric fermentation in cattle is one of the major sources of anthropogenic greenhouse gas emission in the United States and worldwide. National estimates of methane emissions rely on mathematical models such as the one recommended by the Intergovernmental Panel for Climate Change (IPCC). Models used for prediction of methane emissions from cattle range from empirical to mechanistic with varying input requirements. Two empirical and 2 mechanistic models (COWPOLL and MOLLY) were evaluated for their prediction ability using individual cattle measurements. Model selection was based on mean square prediction error (MSPE), concordance correlation coefficient, and residuals vs. predicted values analyses. In dairy cattle, COWPOLL had the lowest root MSPE and greatest accuracy and precision of predicting methane emissions (correlation coefficient estimate = 0.75). The model simulated differences in diet more accurately than the other models, and the residuals vs. predicted value analysis showed no mean bias (P = 0.71). In feedlot cattle, MOLLY had the lowest root MSPE with almost all errors from random sources (correlation coefficient estimate = 0.69). The IPCC model also had good agreement with observed values, and no significant mean (P = 0.74) or linear bias (P = 0.11) was detected when residuals were plotted against predicted values. A fixed methane conversion factor (Ym) might be an easier alternative to diet-dependent variable Ym. Based on the results, the 2 mechanistic models were used to simulate methane emissions from representative US diets and were compared with the IPCC model. The average Ym in dairy cows was 5.63% of GE (range 3.78 to 7.43%) compared with 6.5% +/- 1% recommended by IPCC. In feedlot cattle, the average Ym was 3.88% (range 3.36 to 4.56%) compared with 3% +/- 1% recommended by IPCC. Based on our simulations, using IPCC values can result in an overestimate of about 12.5% and underestimate of emissions by about 9.8% for dairy and feedlot cattle, respectively. In addition to providing improved estimates of emissions based on diets, mechanistic models can be used to assess mitigation options such as changing source of carbohydrate or addition of fat to decrease methane, which is not possible with empirical models. We recommend national inventories use diet-specific Ym values predicted by mechanistic models to estimate methane emissions from cattle.

Contribution of Ruminal Fungi, Archaea, Protozoa, and Bacteria to the Methane Suppression Caused by Oilseed Supplemented Diets

PubMed Central

Wang, Shaopu; Giller, Katrin; Kreuzer, Michael; Ulbrich, Susanne E.; Braun, Ueli; Schwarm, Angela

2017-01-01

Dietary lipids can suppress methane emission from ruminants, but effects are variable. Especially the role of bacteria, archaea, fungi and protozoa in mediating the lipid effects is unclear. In the present in vitro study, archaea, fungi and protozoa were selectively inhibited by specific agents. This was fully or almost fully successful for fungi and protozoa as well as archaeal activity as determined by the methyl-coenzyme M reductase alpha subunit gene. Five different microbial treatments were generated: rumen fluid being intact (I), without archaea (–A), without fungi (–F), without protozoa (–P) and with bacteria only (–AFP). A forage-concentrate diet given alone or supplemented with crushed full-fat oilseeds of either safflower (Carthamus tinctorius) or poppy (Papaver somniferum) or camelina (Camelina sativa) at 70 g oil kg−1 diet dry matter was incubated. This added up to 20 treatments with six incubation runs per treatment. All oilseeds suppressed methane emission compared to the non-supplemented control. Compared to the non-supplemented control, –F decreased organic matter (OM) degradation, and short-chain fatty acid concentration was greater with camelina and safflower seeds. Methane suppression per OM digested in –F was greater with camelina seeds (−12 vs.−7% with I, P = 0.06), but smaller with poppy seeds (−4 vs. −8% with I, P = 0.03), and not affected with safflower seeds. With –P, camelina seeds decreased the acetate-to-propionate ratio and enhanced the methane suppression per gram dry matter (18 vs. 10% with I, P = 0.08). Hydrogen recovery was improved with –P in any oilseeds compared to non-supplemented control. No methane emission was detected with the –A and –AFP treatments. In conclusion, concerning methanogenesis, camelina seeds seem to exert effects only on archaea and bacteria. By contrast, with safflower and poppy seeds methane was obviously reduced mainly through the interaction with protozoa or archaea associated with protozoa. This demonstrated that the microbial groups differ in their contribution to the methane suppressing effect dependent on the source of lipid. These findings help to understand how lipid supplementation and microbial groups interact, and thus may assist in making this methane mitigation tool more efficient, but await confirmation in vivo. PMID:29033916

Contribution of Ruminal Fungi, Archaea, Protozoa, and Bacteria to the Methane Suppression Caused by Oilseed Supplemented Diets.

PubMed

Wang, Shaopu; Giller, Katrin; Kreuzer, Michael; Ulbrich, Susanne E; Braun, Ueli; Schwarm, Angela

2017-01-01

Dietary lipids can suppress methane emission from ruminants, but effects are variable. Especially the role of bacteria, archaea, fungi and protozoa in mediating the lipid effects is unclear. In the present in vitro study, archaea, fungi and protozoa were selectively inhibited by specific agents. This was fully or almost fully successful for fungi and protozoa as well as archaeal activity as determined by the methyl-coenzyme M reductase alpha subunit gene. Five different microbial treatments were generated: rumen fluid being intact (I), without archaea (-A), without fungi (-F), without protozoa (-P) and with bacteria only (-AFP). A forage-concentrate diet given alone or supplemented with crushed full-fat oilseeds of either safflower ( Carthamus tinctorius ) or poppy ( Papaver somniferum ) or camelina ( Camelina sativa ) at 70 g oil kg -1 diet dry matter was incubated. This added up to 20 treatments with six incubation runs per treatment. All oilseeds suppressed methane emission compared to the non-supplemented control. Compared to the non-supplemented control, -F decreased organic matter (OM) degradation, and short-chain fatty acid concentration was greater with camelina and safflower seeds. Methane suppression per OM digested in -F was greater with camelina seeds (-12 vs.-7% with I, P = 0.06), but smaller with poppy seeds (-4 vs. -8% with I, P = 0.03), and not affected with safflower seeds. With -P, camelina seeds decreased the acetate-to-propionate ratio and enhanced the methane suppression per gram dry matter (18 vs. 10% with I, P = 0.08). Hydrogen recovery was improved with -P in any oilseeds compared to non-supplemented control. No methane emission was detected with the -A and -AFP treatments. In conclusion, concerning methanogenesis, camelina seeds seem to exert effects only on archaea and bacteria. By contrast, with safflower and poppy seeds methane was obviously reduced mainly through the interaction with protozoa or archaea associated with protozoa. This demonstrated that the microbial groups differ in their contribution to the methane suppressing effect dependent on the source of lipid. These findings help to understand how lipid supplementation and microbial groups interact, and thus may assist in making this methane mitigation tool more efficient, but await confirmation in vivo .

Low-Energy, Low-Cost Production of Ethylene by Low- Temperature Oxidative Coupling of Methane

DOE Office of Scientific and Technical Information (OSTI.GOV)

Radaelli, Guido; Chachra, Gaurav; Jonnavittula, Divya

In this project, we develop a catalytic process technology for distributed small-scale production of ethylene by oxidative coupling of methane at low temperatures using an advanced catalyst. The Low Temperature Oxidative Coupling of Methane (LT-OCM) catalyst system is enabled by a novel chemical catalyst and process pioneered by Siluria, at private expense, over the last six years. Herein, we develop the LT-OCM catalyst system for distributed small-scale production of ethylene by identifying and addressing necessary process schemes, unit operations and process parameters that limit the economic viability and mass penetration of this technology to manufacture ethylene at small-scales. The outputmore » of this program is process concepts for small-scale LT-OCM catalyst based ethylene production, lab-scale verification of the novel unit operations adopted in the proposed concept, and an analysis to validate the feasibility of the proposed concepts.« less

Fiber Laser methane sensor with the function of self-diagnose

NASA Astrophysics Data System (ADS)

Li, Yan-fang; Wei, Yu-bin; Shang, Ying; Wang, Chang; Liu, Tong-yu

2012-02-01

Using the technology of tunable diode laser absorption spectroscopy and the technology of micro-electronics, a fiber laser methane sensor based on the microprocessor C8051F410 is given. In this paper, we use the DFB Laser as the light source of the sensor. By tuning temperature and driver current of the DFB laser, we can scan the laser over the methane absorption line, Based on the Beer-Lambert law, through detect the variation of the light power before and after the absorption we realize the methane detection. It makes the real-time and online detection of methane concentration to be true, and it has the advantages just as high accuracy, immunity to other gases , long calibration cycle and so on. The sensor has the function of adaptive gain and self-diagnose. By introducing digital potentiometers, the gain of the photoelectric conversion operational amplifier can be controlled by the microprocessor according to the light power. When the gain and the conversion voltage achieve the set value, then we can consider the sensor in a fault status, and then the software will alarm us to check the status of the probe. So we improved the dependence and the stability of the measured results. At last we give some analysis on the sensor according the field application and according the present working, we have a look of our next work in the distance.

Project M: An Assessment of Mission Assumptions

NASA Technical Reports Server (NTRS)

Edwards, Alycia

2010-01-01

Project M is a mission Johnson Space Center is working on to send an autonomous humanoid robot to the moon (also known as Robonaut 2) in l000 days. The robot will be in a lander, fueled by liquid oxygen and liquid methane, and land on the moon, avoiding any hazardous obstacles. It will perform tasks like maintenance, construction, and simple student experiments. This mission is also being used as inspiration for new advancements in technology. I am considering three of the design assumptions that contribute to determining the mission feasibility: maturity of robotic technology, launch vehicle determination, and the LOX/Methane fueled spacecraft

Optimal Design of Biomass Utilization System for Rural Area Includes Technical and Economic Dimensions

NASA Astrophysics Data System (ADS)

Morioka, Yasuki; Nakata, Toshihiko

In order to design optimal biomass utilization system for rural area, OMNIBUS (The Optimization Model for Neo-Integrated Biomass Utilization System) has been developed. OMNIBUS can derive the optimal system configuration to meet different objective function, such as current account balance, amount of biomass energy supply, and CO2 emission. Most of biomass resources in a focused region e.g. wood biomass, livestock biomass, and crop residues are considered in the model. Conversion technologies considered are energy utilization technologies e.g. direct combustion and methane fermentation, and material utilization technologies e.g. composting and carbonization. Case study in Miyakojima, Okinawa prefecture, has been carried out for several objective functions and constraint conditions. Considering economics of the utilization system as a priority requirement, composting and combustion heat utilization are mainly chosen in the optimal system configuration. However gasification power plant and methane fermentation are included in optimal solutions, only when both biomass energy utilization and CO2 reduction have been set as higher priorities. External benefit of CO2 reduction has large impacts on the system configuration. Provided marginal external benefit of more than 50,000 JPY/t-C, external benefit becomes greater than the revenue from electricity and compost etc. Considering technological learning in the future, expensive technologies such as gasification power plant and methane fermentation will have economic feasibility as well as market competitiveness.

Hydropower's Biogenic Carbon Footprint.

PubMed

Scherer, Laura; Pfister, Stephan

2016-01-01

Global warming is accelerating and the world urgently needs a shift to clean and renewable energy. Hydropower is currently the largest renewable source of electricity, but its contribution to climate change mitigation is not yet fully understood. Hydroelectric reservoirs are a source of biogenic greenhouse gases and in individual cases can reach the same emission rates as thermal power plants. Little is known about the severity of their emissions at the global scale. Here we show that the carbon footprint of hydropower is far higher than previously assumed, with a global average of 173 kg CO2 and 2.95 kg CH4 emitted per MWh of electricity produced. This results in a combined average carbon footprint of 273 kg CO2e/MWh when using the global warming potential over a time horizon of 100 years (GWP100). Nonetheless, this is still below that of fossil energy sources without the use of carbon capture and sequestration technologies. We identified the dams most promising for capturing methane for use as alternative energy source. The spread among the ~1500 hydropower plants analysed in this study is large and highlights the importance of case-by-case examinations.

Climate-Smart Livestock Systems: An Assessment of Carbon Stocks and GHG Emissions in Nicaragua.

PubMed

Gaitán, Lucía; Läderach, Peter; Graefe, Sophie; Rao, Idupulapati; van der Hoek, Rein

2016-01-01

Livestock systems in the tropics can contribute to mitigate climate change by reducing greenhouse gas (GHG) emissions and increasing carbon accumulation. We quantified C stocks and GHG emissions of 30 dual-purpose cattle farms in Nicaragua using farm inventories and lifecycle analysis. Trees in silvo-pastoral systems were the main C stock above-ground (16-24 Mg ha-1), compared with adjacent secondary forests (43 Mg C ha-1). We estimated that methane from enteric fermentation contributed 1.6 kg CO2-eq., and nitrous oxide from excreta 0.4 kg CO2-eq. per kg of milk produced. Seven farms that we classified as climate-smart agriculture (CSA) out of 16 farms had highest milk yields (6.2 kg cow-1day-1) and lowest emissions (1.7 kg CO2-eq. per kg milk produced). Livestock on these farms had higher-quality diets, especially during the dry season, and manure was managed better. Increasing the numbers of CSA farms and improving CSA technology will require better enabling policy and incentives such as payments for ecosystem services.

Climate-Smart Livestock Systems: An Assessment of Carbon Stocks and GHG Emissions in Nicaragua

PubMed Central

Gaitán, Lucía; Läderach, Peter; Graefe, Sophie; Rao, Idupulapati; van der Hoek, Rein

2016-01-01

Livestock systems in the tropics can contribute to mitigate climate change by reducing greenhouse gas (GHG) emissions and increasing carbon accumulation. We quantified C stocks and GHG emissions of 30 dual-purpose cattle farms in Nicaragua using farm inventories and lifecycle analysis. Trees in silvo-pastoral systems were the main C stock above-ground (16–24 Mg ha-1), compared with adjacent secondary forests (43 Mg C ha-1). We estimated that methane from enteric fermentation contributed 1.6 kg CO2-eq., and nitrous oxide from excreta 0.4 kg CO2-eq. per kg of milk produced. Seven farms that we classified as climate-smart agriculture (CSA) out of 16 farms had highest milk yields (6.2 kg cow-1day-1) and lowest emissions (1.7 kg CO2-eq. per kg milk produced). Livestock on these farms had higher-quality diets, especially during the dry season, and manure was managed better. Increasing the numbers of CSA farms and improving CSA technology will require better enabling policy and incentives such as payments for ecosystem services. PMID:28030599

Liquid Oxygen/Liquid Methane Component Technology Development at MSFC

NASA Technical Reports Server (NTRS)

Robinson, Joel W.

2010-01-01

The National Aeronautics & Space Administration (NASA) has identified Liquid Oxygen (LOX)/Liquid Methane (LCH4) as a potential propellant combination for future space vehicles based upon exploration studies. The technology is estimated to have higher performance and lower overall systems mass compared to existing hypergolic propulsion systems. Besides existing in-house risk reduction activities, NASA has solicited from industry their participation on component technologies based on the potential application to the lunar ascent main engine (AME). Contracted and NASA efforts have ranged from valve technologies to engine system testbeds. The application for the AME is anticipated to be an expendable, pressure-fed engine for ascent from the moon at completion of its lunar stay. Additionally, the hardware is expected to provide an abort capability prior to landing, in the event that descent systems malfunction. For the past 4 years, MSFC has been working with the Glenn Research Center and the Johnson Space Center on methane technology development. This paper will focus on efforts specific to MSFC in pursuing ignition, injector performance, chamber material assessments and cryogenic valve technologies. Ignition studies have examined characteristics for torch, spark and microwave systems. Injector testing has yielded insight into combustion performance for shear, swirl and impinging type injectors. The majority of chamber testing has been conducted with ablative and radiatively cooled chambers with planned activities for regenerative and transpiration cooled chambers. Lastly, an effort is underway to examine the long duration exposure issues of cryogenic valve internal components. The paper will summarize the status of these efforts.

Indoor Air Vapor Intrusion Mitigation Approaches

EPA Pesticide Factsheets

The National Risk Management Research Laboratory has developed a technology transfer document regarding management and treatment of vapor intrusion into building structures. This document describes the range of mitigation technologies available.

Isolation, characterization and strain selection of a Paenibacillus species for use as a probiotic to aid in ruminal methane mitigation, nitrate/nitrite detoxification and food safety.

PubMed

Latham, Elizabeth A; Pinchak, William E; Trachsel, Julian; Allen, Heather K; Callaway, Todd R; Nisbet, David J; Anderson, Robin C

2018-04-30

The effects of dietary nitrate and Paenibacillus 79R4 (79R4), a denitrifying bacterium, when co-administered as a probiotic, on methane emissions, nitrate and nitrite-metabolizing capacity and fermentation characteristics were studied in vitro. Mixed populations of rumen microbes inoculated with 79R4 metabolized all levels of nitrite studied after 24 h in vitro incubation. Results from in vitro simulations resulted in up to 2 log 10 colony forming unit reductions in E. coli O157:H7 and Campylobacter jejuni when these were co-cultured with 79R4. Nitrogen gas was the predominant final product of nitrite reduction by 79R4. When tested with nitrate-treated incubations of rumen microbes, 79R4 inoculation (provided to achieve 10 6  cells/mL rumen fluid volume) complemented the ruminal methane-decreasing potential of nitrate (P < 0.05) while concurrently increasing fermentation efficiency and enhancing ruminal nitrate and nitrite-metabolizing activity (P < 0.05) compared to untreated and nitrate only-treated incubations. Copyright © 2018 Elsevier Ltd. All rights reserved.

Two-Dimensional Layered Double Hydroxides for Reactions of Methanation and Methane Reforming in C1 Chemistry

PubMed Central

Li, Panpan; Altaf, Naveed; Zhu, Mingyuan; Li, Jiangbing; Dai, Bin; Wang, Qiang

2018-01-01

CH4 as the paramount ingredient of natural gas plays an eminent role in C1 chemistry. CH4 catalytically converted to syngas is a significant route to transmute methane into high value-added chemicals. Moreover, the CO/CO2 methanation reaction is one of the potent technologies for CO2 valorization and the coal-derived natural gas production process. Due to the high thermal stability and high extent of dispersion of metallic particles, two-dimensional mixed metal oxides through calcined layered double hydroxides (LDHs) precursors are considered as the suitable supports or catalysts for both the reaction of methanation and methane reforming. The LDHs displayed compositional flexibility, small crystal sizes, high surface area and excellent basic properties. In this paper, we review previous works of LDHs applied in the reaction of both methanation and methane reforming, focus on the LDH-derived catalysts, which exhibit better catalytic performance and thermal stability than conventional catalysts prepared by impregnation method and also discuss the anti-coke ability and anti-sintering ability of LDH-derived catalysts. We believe that LDH-derived catalysts are promising materials in the heterogeneous catalytic field and provide new insight for the design of advance LDH-derived catalysts worthy of future research. PMID:29385064

Environmental factors influencing landfill gas biofiltration: Lab scale study on methanotrophic bacteria growth.

PubMed

Amodeo, Corrado; Sofo, Adriano; Tito, Maria Teresa; Scopa, Antonio; Masi, Salvatore; Pascale, Raffaella; Mancini, Ignazio M; Caniani, Donatella

2018-03-29

The post-management of landfills represents an important challenge for landfill gas treatment. Traditional systems (energy recovery, flares, etc.) present technical problems in treating flow with low methane (CH 4 ) concentrations. The objective of this study was to isolate methanotrophic bacteria from a field-scale biofilter in order to study the bacteria in laboratories and evaluate the environmental factors that mostly influence Microbial Aerobic Methane Oxidation (MAMO). The soil considered was sampled from the biofilter located in the landfill of Venosa (Basilicata Region, Italy) and it was mainly composed of wood chips and compost. The results showed that methanotrophic microorganisms are mainly characterized by a slow growth and a significant sensitivity to CH 4 levels. Temperature and nitrogen (N) also have a very important role on their development. On the basis of the results, biofilters for biological CH 4 oxidation can be considered a viable alternative to mitigate CH 4 emissions from landfills.

A 21st-century shift from fossil-fuel to biogenic methane emissions indicated by ¹³CH₄.

PubMed

Schaefer, Hinrich; Mikaloff Fletcher, Sara E; Veidt, Cordelia; Lassey, Keith R; Brailsford, Gordon W; Bromley, Tony M; Dlugokencky, Edward J; Michel, Sylvia E; Miller, John B; Levin, Ingeborg; Lowe, Dave C; Martin, Ross J; Vaughn, Bruce H; White, James W C

2016-04-01

Between 1999 and 2006, a plateau interrupted the otherwise continuous increase of atmospheric methane concentration [CH4] since preindustrial times. Causes could be sink variability or a temporary reduction in industrial or climate-sensitive sources. We reconstructed the global history of [CH4] and its stable carbon isotopes from ice cores, archived air, and a global network of monitoring stations. A box-model analysis suggests that diminishing thermogenic emissions, probably from the fossil-fuel industry, and/or variations in the hydroxyl CH4 sink caused the [CH4] plateau. Thermogenic emissions did not resume to cause the renewed [CH4] rise after 2006, which contradicts emission inventories. Post-2006 source increases are predominantly biogenic, outside the Arctic, and arguably more consistent with agriculture than wetlands. If so, mitigating CH4 emissions must be balanced with the need for food production. Copyright © 2016, American Association for the Advancement of Science.

Methane Emission and Milk Production of Dairy Cows Grazing Pastures Rich in Legumes or Rich in Grasses in Uruguay.

PubMed

Dini, Yoana; Gere, José; Briano, Carolina; Manetti, Martin; Juliarena, Paula; Picasso, Valentin; Gratton, Roberto; Astigarraga, Laura

2012-06-08

Understanding the impact of changing pasture composition on reducing emissions of GHGs in dairy grazing systems is an important issue to mitigate climate change. The aim of this study was to estimate daily CH₄ emissions of dairy cows grazing two mixed pastures with contrasting composition of grasses and legumes: L pasture with 60% legumes on Dry Matter (DM) basis and G pasture with 75% grasses on DM basis. Milk production and CH₄ emissions were compared over two periods of two weeks during spring using eight lactating Holstein cows in a 2 × 2 Latin square design. Herbage organic matter intake (HOMI) was estimated by chromic oxide dilution and herbage organic matter digestibility (OMD) was estimated by faecal index. Methane emission was estimated by using the sulfur hexafluoride (SF6) tracer technique adapted to collect breath samples over 5-day periods. OMD (0.71) and HOMI (15.7 kg OM) were not affected by pasture composition. Milk production (20.3 kg/d), milk fat yield (742 g/d) and milk protein yield (667 g/d) were similar for both pastures. This may be explained by the high herbage allowance (30 kg DM above 5 cm/cow) which allowed the cows to graze selectively, in particular in grass sward. Similarly, methane emission expressed as absolute value (368 g/d or 516 L/d) or expressed as methane yield (6.6% of Gross Energy Intake (GEI)) was not affected by treatments. In conclusion, at high herbage allowance, the quality of the diet selected by grazing cows did not differ between pastures rich in legumes or rich in grasses, and therefore there was no effect on milk or methane production.

Development of the Vista Methane Emissions Inventory for Southern California: A GIS-Based Approach for Mapping Methane Emissions

NASA Astrophysics Data System (ADS)

Carranza, V.; Frausto-Vicencio, I.; Rafiq, T.; Verhulst, K. R.; Hopkins, F. M.; Rao, P.; Duren, R. M.; Miller, C. E.

2016-12-01

Atmospheric methane (CH4) is the second most prevalent anthropogenic greenhouse gas. Improved estimates of CH4 emissions from cities is essential for carbon cycle science and climate mitigation efforts. Development of spatially-resolved carbon emissions data sets may offer significant advances in understanding and managing carbon emissions from cities. Urban CH4 emissions in particular require spatially resolved emission maps to help resolve uncertainties in the CH4 budget. This study presents a Geographic Information System (GIS)-based approach to mapping CH4 emissions using locations of infrastructure known to handle and emit methane. We constrain the spatial distribution of sources to the facility level for the major CH4 emitting sources in the South Coast Air Basin. GIS spatial modeling was combined with publicly available datasets to determine the distribution of potential CH4 sources. The datasets were processed and validated to ensure accuracy in the location of individual sources. This information was then used to develop the Vista emissions prior, which is a one-year long, spatially-resolved CH4 emissions estimate. Methane emissions were calculated and spatially allocated to produce 1 km x 1 km gridded CH4 emission map spanning the Los Angeles Basin. In future work, the Vista CH4 emissions prior will be compared with existing, coarser-resolution emissions estimates and will be evaluated in inverse modeling studies using atmospheric observations. The Vista CH4 emissions inventory presents the first detailed spatial maps of CH4 sources and emissions estimates in the Los Angeles Basin and is a critical step towards sectoral attribution of CH4 emissions at local to regional scales.

Effect of feeding of blend of essential oils on methane production, growth, and nutrient utilization in growing buffaloes

PubMed Central

2018-01-01

Objective An experiment was conducted to study the effect of a blend of essential oils (BEO) on enteric methane emission and growth performance of buffaloes (Bubalus bubalis). Methods Twenty one growing male buffaloes (average body weight of 279±9.3 kg) were divided in to three groups. The animals of all the three groups were fed on a ration consisting of wheat straw and concentrate mixture targeting 500 g daily live weight gain. The three dietary groups were; Group 1, control without additive; Group 2 and 3, supplemented with BEO at 0.15 and 0.30 mL/kg of dry matter intake (DMI), respectively. Results During six months feeding trial, the intake and digestibility of dry matter and nutrients (organic matter, crude protein, ether extract, neutral detergent fibre, and acid detergent fibre) were similar in all the groups. The average body weight gain was tended to improve (p = 0.084) in Group 2 and Group 3 as compared to control animals. Feeding of BEO did not affect feed conversion efficiency of the animals. The calves of all the three groups were in positive nitrogen balance with no difference in nitrogen metabolism. During respiration chamber studies the methane production (L/kg DMI and L/kg digestible dry matter intake was significantly (p<0.001) lower in Group 2 and Group 3 as compared to control animals. Conclusion The results indicated that the BEO tested in the present study have shown potential to reduce enteric methane production without compromising the nutrient utilization and animal performance and could be further explored for its use as feed additive to mitigate enteric methane production in livestock. PMID:28231698

Airborne methane remote measurements reveal heavy-tail flux distribution in Four Corners region

PubMed Central

Thorpe, Andrew K.; Thompson, David R.; Hulley, Glynn; Kort, Eric Adam; Vance, Nick; Borchardt, Jakob; Krings, Thomas; Gerilowski, Konstantin; Sweeney, Colm; Conley, Stephen; Bue, Brian D.; Aubrey, Andrew D.; Hook, Simon; Green, Robert O.

2016-01-01

Methane (CH4) impacts climate as the second strongest anthropogenic greenhouse gas and air quality by influencing tropospheric ozone levels. Space-based observations have identified the Four Corners region in the Southwest United States as an area of large CH4 enhancements. We conducted an airborne campaign in Four Corners during April 2015 with the next-generation Airborne Visible/Infrared Imaging Spectrometer (near-infrared) and Hyperspectral Thermal Emission Spectrometer (thermal infrared) imaging spectrometers to better understand the source of methane by measuring methane plumes at 1- to 3-m spatial resolution. Our analysis detected more than 250 individual methane plumes from fossil fuel harvesting, processing, and distributing infrastructures, spanning an emission range from the detection limit ∼ 2 kg/h to 5 kg/h through ∼ 5,000 kg/h. Observed sources include gas processing facilities, storage tanks, pipeline leaks, and well pads, as well as a coal mine venting shaft. Overall, plume enhancements and inferred fluxes follow a lognormal distribution, with the top 10% emitters contributing 49 to 66% to the inferred total point source flux of 0.23 Tg/y to 0.39 Tg/y. With the observed confirmation of a lognormal emission distribution, this airborne observing strategy and its ability to locate previously unknown point sources in real time provides an efficient and effective method to identify and mitigate major emissions contributors over a wide geographic area. With improved instrumentation, this capability scales to spaceborne applications [Thompson DR, et al. (2016) Geophys Res Lett 43(12):6571–6578]. Further illustration of this potential is demonstrated with two detected, confirmed, and repaired pipeline leaks during the campaign. PMID:27528660

Impact of reduced water consumption on sulfide and methane production in rising main sewers.

PubMed

Sun, Jing; Hu, Shihu; Sharma, Keshab Raj; Bustamante, Heriberto; Yuan, Zhiguo

2015-05-01

Reduced water consumption (RWC), for water conservation purposes, is expected to change the wastewater composition and flow conditions in sewer networks and affect the in-sewer transformation processes. In this study, the impact of reduced water consumption on sulfide and methane production in rising main sewers was investigated. Two lab-scale rising main sewer systems fed with wastewater of different strength and flow rates were operated to mimic sewers under normal and RWC conditions (water consumption reduced by 40%). Sulfide concentration under the RWC condition increased by 0.7-8.0 mg-S/L, depending on the time of a day. Batch test results showed that the RWC did not change the sulfate-reducing activity of sewer biofilms, the increased sulfide production being mainly due to longer hydraulic retention time (HRT). pH in the RWC system was about 0.2 units lower than that in the normal system, indicating that more sulfide would be in molecular form under the RWC condition, which would result in increased sulfide emission to the atmosphere as confirmed by the model simulation. Model based analysis showed that the cost for chemical dosage for sulfide mitigation would increase significantly per unit volume of sewage, although the total cost would decrease due to a lower sewage flow. The dissolved methane concentration under the RWC condition was over two times higher than that under the normal flow condition and the total methane discharge was about 1.5 times higher, which would potentially result in higher greenhouse gas emissions. Batch tests showed that the methanogenic activity of sewer biofilms increased under the RWC condition, which along with the longer HRT, led to increased methane production. Copyright © 2015 Elsevier Ltd. All rights reserved.

Phosphoketolase overexpression increases biomass and lipid yield from methane in an obligate methanotrophic biocatalyst

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henard, Calvin A.; Smith, Holly K.; Guarnieri, Michael T.

Microbial conversion of methane to high-value bio-based chemicals and materials offers a path to mitigate GHG emissions and valorize this abundant-yet -underutilized carbon source. In addition to fermentation optimization strategies, rational methanotrophic bacterial strain engineering offers a means to reach industrially relevant titers, carbon yields, and productivities of target products. The phosphoketolase pathway functions in heterofermentative bacteria where carbon flux through two sugar catabolic pathways to mixed acids (lactic acid and acetic acid) increases cellular ATP production. Importantly, this pathway also serves as an alternative route to produce acetyl-CoA that bypasses the CO 2 lost through pyruvate decarboxylation in themore » Embden-Meyerhof-Parnas pathway. Thus, the phosphoketolase pathway can be leveraged for carbon efficient biocatalysis to acetyl-CoA-derived intermediates and products. Here, we show that the industrially promising methane biocatalyst, Methylomicrobium buryatense, encodes two phosphoketolase isoforms that are expressed in methanol- and methane-grown cells. Overexpression of the PktB isoform led to a 2-fold increase in intracellular acetyl-CoA concentration, and a 2.6-fold yield enhancement from methane to microbial biomass and lipids compared to wild-type, increasing the potential for methanotroph lipid-based fuel production. Off-gas analysis and metabolite profiling indicated that global metabolic rearrangements, including significant increases in post-translational protein acetylation and gene expression of the tetrahydromethanopterin-linked pathway, along with decreases in several excreted products, coincided with the superior biomass and lipid yield observed in the engineered strain. Further, these data suggest that phosphoketolase may play a key regulatory role in methanotrophic bacterial metabolism. As a result, given that acetyl-CoA is a key intermediate in several biosynthetic pathways, phosphoketolase overexpression offers a viable strategy to enhance the economics of an array of biological methane conversion processes.« less

Phosphoketolase overexpression increases biomass and lipid yield from methane in an obligate methanotrophic biocatalyst.

PubMed

Henard, Calvin A; Smith, Holly K; Guarnieri, Michael T

2017-05-01

Microbial conversion of methane to high-value bio-based fuels, chemicals, and materials offers a path to mitigate GHG emissions and valorize this abundant-yet -underutilized carbon source. In addition to fermentation optimization strategies, rational methanotrophic bacterial strain engineering offers a means to reach industrially relevant titers, carbon yields, and productivities of target products. The phosphoketolase pathway functions in heterofermentative bacteria where carbon flux through two sugar catabolic pathways to mixed acids (lactic acid and acetic acid) increases cellular ATP production. Importantly, this pathway also serves as an alternative route to produce acetyl-CoA that bypasses the CO 2 lost through pyruvate decarboxylation in the Embden-Meyerhof-Parnas pathway. Thus, the phosphoketolase pathway can be leveraged for carbon efficient biocatalysis to acetyl-CoA-derived intermediates and products. Here, we show that the industrially promising methane biocatalyst, Methylomicrobium buryatense, encodes two phosphoketolase isoforms that are expressed in methanol- and methane-grown cells. Overexpression of the PktB isoform led to a 2-fold increase in intracellular acetyl-CoA concentration, and a 2.6-fold yield enhancement from methane to microbial biomass and lipids compared to wild-type, increasing the potential for methanotroph lipid-based fuel production. Off-gas analysis and metabolite profiling indicated that global metabolic rearrangements, including significant increases in post-translational protein acetylation and gene expression of the tetrahydromethanopterin-linked pathway, along with decreases in several excreted products, coincided with the superior biomass and lipid yield observed in the engineered strain. Further, these data suggest that phosphoketolase may play a key regulatory role in methanotrophic bacterial metabolism. Given that acetyl-CoA is a key intermediate in several biosynthetic pathways, phosphoketolase overexpression offers a viable strategy to enhance the economics of an array of biological methane conversion processes. Copyright © 2017. Published by Elsevier Inc.

Phosphoketolase overexpression increases biomass and lipid yield from methane in an obligate methanotrophic biocatalyst

DOE PAGES

Henard, Calvin A.; Smith, Holly K.; Guarnieri, Michael T.

2017-04-02

Microbial conversion of methane to high-value bio-based chemicals and materials offers a path to mitigate GHG emissions and valorize this abundant-yet -underutilized carbon source. In addition to fermentation optimization strategies, rational methanotrophic bacterial strain engineering offers a means to reach industrially relevant titers, carbon yields, and productivities of target products. The phosphoketolase pathway functions in heterofermentative bacteria where carbon flux through two sugar catabolic pathways to mixed acids (lactic acid and acetic acid) increases cellular ATP production. Importantly, this pathway also serves as an alternative route to produce acetyl-CoA that bypasses the CO 2 lost through pyruvate decarboxylation in themore » Embden-Meyerhof-Parnas pathway. Thus, the phosphoketolase pathway can be leveraged for carbon efficient biocatalysis to acetyl-CoA-derived intermediates and products. Here, we show that the industrially promising methane biocatalyst, Methylomicrobium buryatense, encodes two phosphoketolase isoforms that are expressed in methanol- and methane-grown cells. Overexpression of the PktB isoform led to a 2-fold increase in intracellular acetyl-CoA concentration, and a 2.6-fold yield enhancement from methane to microbial biomass and lipids compared to wild-type, increasing the potential for methanotroph lipid-based fuel production. Off-gas analysis and metabolite profiling indicated that global metabolic rearrangements, including significant increases in post-translational protein acetylation and gene expression of the tetrahydromethanopterin-linked pathway, along with decreases in several excreted products, coincided with the superior biomass and lipid yield observed in the engineered strain. Further, these data suggest that phosphoketolase may play a key regulatory role in methanotrophic bacterial metabolism. As a result, given that acetyl-CoA is a key intermediate in several biosynthetic pathways, phosphoketolase overexpression offers a viable strategy to enhance the economics of an array of biological methane conversion processes.« less

Current available strategies to mitigate greenhouse gas emissions in livestock systems: an animal welfare perspective.

PubMed

Llonch, P; Haskell, M J; Dewhurst, R J; Turner, S P

2017-02-01

Livestock production is a major contributor to greenhouse gas (GHG) emissions, so will play a significant role in the mitigation effort. Recent literature highlights different strategies to mitigate GHG emissions in the livestock sector. Animal welfare is a criterion of sustainability and any strategy designed to reduce the carbon footprint of livestock production should consider animal welfare amongst other sustainability metrics. We discuss and tabulate the likely relationships and trade-offs between the GHG mitigation potential of mitigation strategies and their welfare consequences, focusing on ruminant species and on cattle in particular. The major livestock GHG mitigation strategies were classified according to their mitigation approach as reducing total emissions (inhibiting methane production in the rumen), or reducing emissions intensity (Ei; reducing CH4 per output unit without directly targeting methanogenesis). Strategies classified as antimethanogenic included chemical inhibitors, electron acceptors (i.e. nitrates), ionophores (i.e. Monensin) and dietary lipids. Increasing diet digestibility, intensive housing, improving health and welfare, increasing reproductive efficiency and breeding for higher productivity were categorized as strategies that reduce Ei. Strategies that increase productivity are very promising ways to reduce the livestock carbon footprint, though in intensive systems this is likely to be achieved at the cost of welfare. Other strategies can effectively reduce GHG emissions whilst simultaneously improving animal welfare (e.g. feed supplementation or improving health). These win-win strategies should be strongly supported as they address both environmental and ethical sustainability. In order to identify the most cost-effective measures for improving environmental sustainability of livestock production, the consequences of current and future strategies for animal welfare must be scrutinized and contrasted against their effectiveness in mitigating climate change.

15 CFR 971.604 - Best available technologies (BAT) and mitigation.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 15 Commerce and Foreign Trade 3 2013-01-01 2013-01-01 false Best available technologies (BAT) and... Environmental Effects § 971.604 Best available technologies (BAT) and mitigation. (a) The Administrator shall..., NOAA is unable either to specify particular equipment or procedures comprising BAT or to define...

15 CFR 971.604 - Best available technologies (BAT) and mitigation.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 15 Commerce and Foreign Trade 3 2011-01-01 2011-01-01 false Best available technologies (BAT) and... Environmental Effects § 971.604 Best available technologies (BAT) and mitigation. (a) The Administrator shall..., NOAA is unable either to specify particular equipment or procedures comprising BAT or to define...

15 CFR 971.604 - Best available technologies (BAT) and mitigation.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 15 Commerce and Foreign Trade 3 2014-01-01 2014-01-01 false Best available technologies (BAT) and... Environmental Effects § 971.604 Best available technologies (BAT) and mitigation. (a) The Administrator shall..., NOAA is unable either to specify particular equipment or procedures comprising BAT or to define...

15 CFR 971.604 - Best available technologies (BAT) and mitigation.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 15 Commerce and Foreign Trade 3 2012-01-01 2012-01-01 false Best available technologies (BAT) and... Environmental Effects § 971.604 Best available technologies (BAT) and mitigation. (a) The Administrator shall..., NOAA is unable either to specify particular equipment or procedures comprising BAT or to define...

An Aerial ``Sniffer Dog'' for Methane

NASA Astrophysics Data System (ADS)

Nathan, Brian; Schaefer, Dave; Zondlo, Mark; Khan, Amir; Lary, David

2012-10-01

The Earth's surface and its atmosphere maintain a ``Radiation Balance.'' Any factor which influences this balance is labeled as a mechanism of ``Radiative Forcing'' (RF). Greenhouse Gas (GHG) concentrations are among the most important forcing mechanisms. Methane, the second-most-abundant noncondensing greenhouse gas, is over 25 times more effective per molecule at radiating heat than the most abundant, Carbon Dioxide. Methane is also the principal component of Natural Gas, and gas leaks can cause explosions. Additionally, massive quantities of methane reside (in the form of natural gas) in underground shale basins. Recent technological advancements--specifically the combination of horizontal drilling and hydraulic fracturing--have allowed drillers access to portions of these ``plays'' which were previously unreachable, leading to an exponential growth in the shale gas industry. Presently, very little is known about the amount of methane which escapes into the global atmosphere from the extraction process. By using remote-controlled robotic helicopters equipped with specially developed trace gas laser sensors, we can get a 3-D profile of where and how methane is being released into the global atmosphere.

Evaluating the Effects of Surface Properties on Methane Detection with the Airborne Visible/Infrared Imaging Spectrometer Next Generation (AVIRIS-NG)

NASA Astrophysics Data System (ADS)

Ayasse, A.; Thorpe, A. K.; Roberts, D. A.; Aubrey, A. D.; Dennison, P. E.; Thompson, D. R.; Frankenberg, C.

2016-12-01

Atmospheric methane has been increasing since the industrial revolution and is thought to be responsible for about 25% of global radiative forcing (Hofman et al., 2006; Montzka et al., 2011). Given the importance of methane to global climate, it is essential that we identify methane sources to better understand the proportion of emissions coming from various sectors. Recently the Airborne Visible-Infrared Imaging Spectrometer Next Generation (AVIRIS-NG) has proven to be a valuable instrument for mapping methane plumes (Frankenberg et al., 2016; Thorpe et al., 2016; Thompson et al., 2015). However, it is important to determine how land cover and albedo affect the ability of AVIRIS-NG to detect methane. This study aims to quantify the effect these surface properties have on detection. To do so we are using a synthetic AVIRIS-NG image that has multiple land cover types, albedos, and methane concentrations and applying the Cluster Tunes Matched Filter (CTMF) algorithm (Funk et al. 2001, Thorpe et al., 2013) to detect methane enhancements within the image. CTMF results are compared to the surface properties to characterize how different surface properties affect detection. We will also evaluate the effect of surface properties with examples of methane plumes observed from oil fields and manure ponds in the San Joaquin Valley of California, two important methane sources (Figure 1). Initial results suggest that darker surfaces, such as water absent sun glint, will make detecting the methane signal challenging, while bright surfaces such as dry soils produce a much clearer signal. Characterizing the effect of surface properties on methane detection is of increasing importance given the application of this technology will likely expand to map methane across a diverse range of emission sources. Figure 1. AVIRIS-NG image acquired Apr. 29, 2015. True color image with a superimposed methane plume from a manure pond. Bright surfaces, such as the dirt road, provide a better surface for retrievals than dark surfaces, such as the vegetation.

Nutrients recycling strategy for microalgae-based CO2 mitigation system

NASA Astrophysics Data System (ADS)

E, Xinyi

Coal-fired electricity production is the major emitter of CO2 and other greenhouse gases including NOx and SO x. Microalgae-based CO2 mitigation systems have been proposed to reduce the net CO2 emission from coal-fired power plants. This study focused on developing an optimum culture media and exploring the possibilities for recycling nutrients, which were added as commercial mineralized chemicals at the beginning of cultivation. In order to release the nutrients embedded in the cells so that they can be used as a nutrient source for new cells, Scenedesmus biomass was digested by anaerobic bacteria. Results showed that thermal pretreatment enhanced the methane production rate for the first 7 days of digestion. Three operational factors were tested: heating temperature, heating duration and NaOH dosage. The combination of 10 min heating with 3˜6% NaOH at 50 °C gave the highest cell wall destruction for all samples except oven-dried algae. The anaerobic digestate, rich in mineralized nutrients including ammonium and phosphate, potassium and magnesium ions, was tested as a possible nutrient source for the algae cultivation. To cope with the high solid content of the digestates, the dosage of the digestates was reduced or the solid particles were removed prior to addition to the microalgae. Both approaches worked well in terms of providing nutrients with minimal effect on light penetration. Using digestates without any sterilization did not cause contamination or other deleterious effects on the Scenedesmus growth rate. Harvesting microalgae cells was critical to ensure a continuous and robust growth rate. The used media could be recycled at least four times without altering the algae growth. Nutrient replenishment was the key for a healthy culture when used media was incorporated. The combination of used media and digestates can sustain a normal algae growth. Life cycle assessment was conducted on the system including the photobioreactor, the anaerobic digester, the biomass settling and dewatering and used media and nutrient recycling. Considering methane as the energy source, the overall energy return of the system was 2.4. CO2 mitigation rate was about 39% under current mitigation system. KEYWORDS: Scenedesmus, urea, anaerobic digestion, used media, life cycle assessment.

MEMO2 - MEthane goes MObile - MEasurements and Modelling - Part 2

NASA Astrophysics Data System (ADS)

Röckmann, Thomas; Walter, Sylvia

2017-04-01

As mitigation of climate change is a key scientific and societal challenge, the 2015 United Nations Climate Change Conference in Paris (COP21) agreed to limit global warming "well below" 2˚ C and, if possible, below 1.5˚ C. Reaching this target requires massive reductions of greenhouse gas emissions, and achieving significant reduction of greenhouse gas emissions is a logical headline targets of the EU climate action and of the H2020 strategy. CH4 emissions are a major contributor to Europe's global warming impact and emissions are not well quantified yet. There are significant discrepancies between official inventories of emissions and estimates derived from direct atmospheric measurement. Effective emission reduction can only be achieved if sources are properly quantified, and mitigation efforts are verified. New advanced combinations of measurement and modelling are needed to archive such quantification. MEMO2 will contribute to the targets of the EU with a focus on methane (CH4). The project will bridge the gap between large-scale scientific estimates from in situ monitoring programs and the 'bottom-up' estimates of emissions from local sources that are used in the national reporting by I) developing new and advanced mobile methane (CH4) measurements tools and networks, II) isotopic source identification, and III) modelling at different scales. Within the project qualified scientists will be educated in the use and implementation of interdisciplinary knowledge and techniques that are essential to meet and verify emission reduction goals. MEMO2 will facilitate intensive collaboration between the largely academic greenhouse gas monitoring community and non-academic partners who are responsible for evaluating and reporting greenhouse gas emissions to policy makers. MEMO2 is a European Training Network with more than 20 collaborators from 7 countries. It is a 4-years project and we will present the project and its objectives to the scientific community to foster collaboration and scientific exchange from the beginning.

Assessment and mitigation of errors associated with a large-scale field investigation of methane emissions from the Marcellus Shale

NASA Astrophysics Data System (ADS)

Caulton, D.; Golston, L.; Li, Q.; Bou-Zeid, E.; Pan, D.; Lane, H.; Lu, J.; Fitts, J. P.; Zondlo, M. A.

2015-12-01

Recent work suggests the distribution of methane emissions from fracking operations is a skewed distributed with a small percentage of emitters contributing a large proportion of the total emissions. In order to provide a statistically robust distributions of emitters and determine the presence of super-emitters, errors in current techniques need to be constrained and mitigated. The Marcellus shale, the most productive natural gas shale field in the United States, has received less intense focus for well-level emissions and is here investigated to provide the distribution of methane emissions. In July of 2015 approximately 250 unique well pads were sampled using the Princeton Atmospheric Chemistry Mobile Acquisition Node (PAC-MAN). This mobile lab includes a Garmin GPS unit, Vaisala weather station (WTX520), LICOR 7700 CH4 open path sensor and LICOR 7500 CO2/H2O open path sensor. Sampling sites were preselected based on wind direction, sampling distance and elevation grade. All sites were sampled during low boundary layer conditions (600-1000 and 1800-2200 local time). The majority of sites were sampled 1-3 times while selected test sites were sampled multiple times or resampled several times during the day. For selected sites a sampling tower was constructed consisting of a Metek uSonic-3 Class A sonic anemometer, and an additional LICOR 7700 and 7500. Data were recorded for at least one hour at these sites. A robust study and inter-comparison of different methodologies will be presented. The Gaussian plume model will be used to calculate fluxes for all sites and compare results from test sites with multiple passes. Tower data is used to provide constraints on the Gaussian plume model. Additionally, Large Eddy Simulation (LES) modeling will be used to calculate emissions from the tower sites. Alternative techniques will also be discussed. Results from these techniques will be compared to identify best practices and provide robust error estimates.

Airborne Quantification of Methane Emissions in the San Francisco Bay Area of California

NASA Astrophysics Data System (ADS)

Guha, A.; Newman, S.; Martien, P. T.; Young, A.; Hilken, H.; Faloona, I. C.; Conley, S.

2017-12-01

The Bay Area Air Quality Management District, the San Francisco Bay Area's air quality regulatory agency, has set a goal to reduce the region's greenhouse gas (GHG) emissions 80% below 1990 levels by 2050, consistent with the State of California's climate protection goal. The Air District maintains a regional GHG emissions inventory that includes emissions estimates and projections which influence the agency's programs and regulatory activities. The Air District is currently working to better characterize methane emissions in the GHG inventory through source-specific measurements, to resolve differences between top-down regional estimates (Fairley and Fischer, 2015; Jeong et al., 2016) and the bottom-up inventory. The Air District funded and participated in a study in Fall 2016 to quantify methane emissions from a variety of sources from an instrumented Mooney aircraft. This study included 40 hours of cylindrical vertical profile flights that combined methane and wind measurements to derive mass emission rates. Simultaneous measurements of ethane provided source-apportionment between fossil-based and biological methane sources. The facilities sampled included all five refineries in the region, five landfills, two dairy farms and three wastewater treatment plants. The calculated mass emission rates were compared to bottom-up rates generated by the Air District and to those from facility reports to the US EPA as part of the mandatory GHG reporting program. Carbon dioxide emission rates from refineries are found to be similar to bottom-up estimates for all sources, supporting the efficacy of the airborne measurement methodology. However, methane emission estimates from the airborne method showed significant differences for some source categories. For example, methane emission estimates based on airborne measurements were up to an order of magnitude higher for refineries, and up to five times higher for landfills compared to bottom-up methods, suggesting significant underestimation in the inventories and self-reported estimates. Future measurements over the same facilities will reveal if we have seasonal and process-dependent trends in emissions. This will provide a basis for rule making and for designing mitigation and control actions.

Anaerobic Methane Oxidation Driven by Microbial Reduction of Natural Organic Matter in a Tropical Wetland

PubMed Central

Valenzuela, Edgardo I.; Prieto-Davó, Alejandra; López-Lozano, Nguyen E.; Hernández-Eligio, Alberto; Vega-Alvarado, Leticia; Juárez, Katy; García-González, Ana Sarahí; López, Mercedes G.

2017-01-01

ABSTRACT Wetlands constitute the main natural source of methane on Earth due to their high content of natural organic matter (NOM), but key drivers, such as electron acceptors, supporting methanotrophic activities in these habitats are poorly understood. We performed anoxic incubations using freshly collected sediment, along with water samples harvested from a tropical wetland, amended with 13C-methane (0.67 atm) to test the capacity of its microbial community to perform anaerobic oxidation of methane (AOM) linked to the reduction of the humic fraction of its NOM. Collected evidence demonstrates that electron-accepting functional groups (e.g., quinones) present in NOM fueled AOM by serving as a terminal electron acceptor. Indeed, while sulfate reduction was the predominant process, accounting for up to 42.5% of the AOM activities, the microbial reduction of NOM concomitantly occurred. Furthermore, enrichment of wetland sediment with external NOM provided a complementary electron-accepting capacity, of which reduction accounted for ∼100 nmol 13CH4 oxidized · cm−3 · day−1. Spectroscopic evidence showed that quinone moieties were heterogeneously distributed in the wetland sediment, and their reduction occurred during the course of AOM. Moreover, an enrichment derived from wetland sediments performing AOM linked to NOM reduction stoichiometrically oxidized methane coupled to the reduction of the humic analogue anthraquinone-2,6-disulfonate. Microbial populations potentially involved in AOM coupled to microbial reduction of NOM were dominated by divergent biota from putative AOM-associated archaea. We estimate that this microbial process potentially contributes to the suppression of up to 114 teragrams (Tg) of CH4 · year−1 in coastal wetlands and more than 1,300 Tg · year−1, considering the global wetland area. IMPORTANCE The identification of key processes governing methane emissions from natural systems is of major importance considering the global warming effects triggered by this greenhouse gas. Anaerobic oxidation of methane (AOM) coupled to the microbial reduction of distinct electron acceptors plays a pivotal role in mitigating methane emissions from ecosystems. Given their high organic content, wetlands constitute the largest natural source of atmospheric methane. Nevertheless, processes controlling methane emissions in these environments are poorly understood. Here, we provide tracer analysis with 13CH4 and spectroscopic evidence revealing that AOM linked to the microbial reduction of redox functional groups in natural organic matter (NOM) prevails in a tropical wetland. We suggest that microbial reduction of NOM may largely contribute to the suppression of methane emissions from tropical wetlands. This is a novel avenue within the carbon cycle in which slowly decaying NOM (e.g., humic fraction) in organotrophic environments fuels AOM by serving as a terminal electron acceptor. PMID:28341676

Anaerobic Methane Oxidation Driven by Microbial Reduction of Natural Organic Matter in a Tropical Wetland.

PubMed

Valenzuela, Edgardo I; Prieto-Davó, Alejandra; López-Lozano, Nguyen E; Hernández-Eligio, Alberto; Vega-Alvarado, Leticia; Juárez, Katy; García-González, Ana Sarahí; López, Mercedes G; Cervantes, Francisco J

2017-06-01

Wetlands constitute the main natural source of methane on Earth due to their high content of natural organic matter (NOM), but key drivers, such as electron acceptors, supporting methanotrophic activities in these habitats are poorly understood. We performed anoxic incubations using freshly collected sediment, along with water samples harvested from a tropical wetland, amended with 13 C-methane (0.67 atm) to test the capacity of its microbial community to perform anaerobic oxidation of methane (AOM) linked to the reduction of the humic fraction of its NOM. Collected evidence demonstrates that electron-accepting functional groups (e.g., quinones) present in NOM fueled AOM by serving as a terminal electron acceptor. Indeed, while sulfate reduction was the predominant process, accounting for up to 42.5% of the AOM activities, the microbial reduction of NOM concomitantly occurred. Furthermore, enrichment of wetland sediment with external NOM provided a complementary electron-accepting capacity, of which reduction accounted for ∼100 nmol 13 CH 4 oxidized · cm -3 · day -1 Spectroscopic evidence showed that quinone moieties were heterogeneously distributed in the wetland sediment, and their reduction occurred during the course of AOM. Moreover, an enrichment derived from wetland sediments performing AOM linked to NOM reduction stoichiometrically oxidized methane coupled to the reduction of the humic analogue anthraquinone-2,6-disulfonate. Microbial populations potentially involved in AOM coupled to microbial reduction of NOM were dominated by divergent biota from putative AOM-associated archaea. We estimate that this microbial process potentially contributes to the suppression of up to 114 teragrams (Tg) of CH 4 · year -1 in coastal wetlands and more than 1,300 Tg · year -1 , considering the global wetland area. IMPORTANCE The identification of key processes governing methane emissions from natural systems is of major importance considering the global warming effects triggered by this greenhouse gas. Anaerobic oxidation of methane (AOM) coupled to the microbial reduction of distinct electron acceptors plays a pivotal role in mitigating methane emissions from ecosystems. Given their high organic content, wetlands constitute the largest natural source of atmospheric methane. Nevertheless, processes controlling methane emissions in these environments are poorly understood. Here, we provide tracer analysis with 13 CH 4 and spectroscopic evidence revealing that AOM linked to the microbial reduction of redox functional groups in natural organic matter (NOM) prevails in a tropical wetland. We suggest that microbial reduction of NOM may largely contribute to the suppression of methane emissions from tropical wetlands. This is a novel avenue within the carbon cycle in which slowly decaying NOM (e.g., humic fraction) in organotrophic environments fuels AOM by serving as a terminal electron acceptor. Copyright © 2017 American Society for Microbiology.

Mixed fuel strategy for carbon deposition mitigation in solid oxide fuel cells at intermediate temperatures.

PubMed

Su, Chao; Chen, Yubo; Wang, Wei; Ran, Ran; Shao, Zongping; Diniz da Costa, João C; Liu, Shaomin

2014-06-17

In this study, we propose and experimentally verified that methane and formic acid mixed fuel can be employed to sustain solid oxide fuel cells (SOFCs) to deliver high power outputs at intermediate temperatures and simultaneously reduce the coke formation over the anode catalyst. In this SOFC system, methane itself was one part of the fuel, but it also played as the carrier gas to deliver the formic acid to reach the anode chamber. On the other hand, the products from the thermal decomposition of formic acid helped to reduce the carbon deposition from methane cracking. In order to clarify the reaction pathways for carbon formation and elimination occurring in the anode chamber during the SOFC operation, O2-TPO and SEM analysis were carried out together with the theoretical calculation. Electrochemical tests demonstrated that stable and high power output at an intermediate temperature range was well-maintained with a peak power density of 1061 mW cm(-2) at 750 °C. With the synergic functions provided by the mixed fuel, the SOFC was running for 3 days without any sign of cell performance decay. In sharp contrast, fuelled by pure methane and tested at similar conditions, the SOFC immediately failed after running for only 30 min due to significant carbon deposition. This work opens a new way for SOFC to conquer the annoying problem of carbon deposition just by properly selecting the fuel components to realize their synergic effects.

Sabatier Reactor System Integration with Microwave Plasma Methane Pyrolysis Post-Processor for Closed-Loop Hydrogen Recovery

NASA Technical Reports Server (NTRS)

Abney, Morgan B.; Miller, Lee A.; Williams, Tom

2010-01-01

The Carbon Dioxide Reduction Assembly (CRA) designed and developed for the International Space Station (ISS) represents the state-of-the-art in carbon dioxide reduction (CDRe) technology. The CRA produces water and methane by reducing carbon dioxide with hydrogen via the Sabatier reaction. The water is recycled to the Oxygen Generation Assembly (OGA) and the methane is vented overboard resulting in a net loss of hydrogen. The proximity to earth and the relative ease of logistics resupply from earth allow for a semi-closed system on ISS. However, long-term manned space flight beyond low earth orbit (LEO) dictates a more thoroughly closed-loop system involving significantly higher recovery of hydrogen, and subsequent recovery of oxygen, to minimize costs associated with logistics resupply beyond LEO. The open-loop ISS system for CDRe can be made closed-loop for follow-on missions by further processing methane to recover hydrogen. For this purpose, a process technology has been developed that employs a microwave-generated plasma to reduce methane to hydrogen and acetylene resulting in 75% theoretical recovery of hydrogen. In 2009, a 1-man equivalent Plasma Pyrolysis Assembly (PPA) was delivered to the National Aeronautics and Space Administration (NASA) for technical evaluation. The PPA has been integrated with a Sabatier Development Unit (SDU). The integrated process configuration incorporates a sorbent bed to eliminate residual carbon dioxide and water vapor in the Sabatier methane product stream before it enters the PPA. This paper provides detailed information on the stand-alone and integrated performance of both the PPA and SDU. Additionally, the integrated test stand design and anticipated future work are discussed.

Property rights regimes to optimize natural resource use - future CBM development and sustainability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eaton, C.; Ingelson, A.; Knopff, R.

2007-04-01

Property rights regimes that promote sustainable development in the context of coalbed methane (CBM) exploration and production recognize and optimize the value of multiple natural resources including minerals, water, flora, and fauna. Institutional mechanisms that account for and mitigate both the short- and long-term external impacts from CBM development promote sustainability. The long-term potential for a vibrant recreational and tourist economy on a particular landscape may be compromised by overly shortsighted mineral resource extraction.

Sensitivity studies for a space-based methane lidar mission

NASA Astrophysics Data System (ADS)

Kiemle, C.; Quatrevalet, M.; Ehret, G.; Amediek, A.; Fix, A.; Wirth, M.

2011-10-01

Methane is the third most important greenhouse gas in the atmosphere after water vapour and carbon dioxide. A major handicap to quantify the emissions at the Earth's surface in order to better understand biosphere-atmosphere exchange processes and potential climate feedbacks is the lack of accurate and global observations of methane. Space-based integrated path differential absorption (IPDA) lidar has potential to fill this gap, and a Methane Remote Lidar Mission (MERLIN) on a small satellite in polar orbit was proposed by DLR and CNES in the frame of a German-French climate monitoring initiative. System simulations are used to identify key performance parameters and to find an advantageous instrument configuration, given the environmental, technological, and budget constraints. The sensitivity studies use representative averages of the atmospheric and surface state to estimate the measurement precision, i.e. the random uncertainty due to instrument noise. Key performance parameters for MERLIN are average laser power, telescope size, orbit height, surface reflectance, and detector noise. A modest-size lidar instrument with 0.45 W average laser power and 0.55 m telescope diameter on a 506 km orbit could provide 50-km averaged methane column measurement along the sub-satellite track with a precision of about 1% over vegetation. The use of a methane absorption trough at 1.65 μm improves the near-surface measurement sensitivity and vastly relaxes the wavelength stability requirement that was identified as one of the major technological risks in the pre-phase A studies for A-SCOPE, a space-based IPDA lidar for carbon dioxide at the European Space Agency. Minimal humidity and temperature sensitivity at this wavelength position will enable accurate measurements in tropical wetlands, key regions with largely uncertain methane emissions. In contrast to actual passive remote sensors, measurements in Polar Regions will be possible and biases due to aerosol layers and thin ice clouds will be minimised.

Sensitivity studies for a space-based methane lidar mission

NASA Astrophysics Data System (ADS)

Kiemle, C.; Quatrevalet, M.; Ehret, G.; Amediek, A.; Fix, A.; Wirth, M.

2011-06-01

Methane is the third most important greenhouse gas in the atmosphere after water vapour and carbon dioxide. A major handicap to quantify the emissions at the Earth's surface in order to better understand biosphere-atmosphere exchange processes and potential climate feedbacks is the lack of accurate and global observations of methane. Space-based integrated path differential absorption (IPDA) lidar has potential to fill this gap, and a Methane Remote Lidar Mission (MERLIN) on a small satellite in Polar orbit was proposed by DLR and CNES in the frame of a German-French climate monitoring initiative. System simulations are used to identify key performance parameters and to find an advantageous instrument configuration, given the environmental, technological, and budget constraints. The sensitivity studies use representative averages of the atmospheric and surface state to estimate the measurement precision, i.e. the random uncertainty due to instrument noise. Key performance parameters for MERLIN are average laser power, telescope size, orbit height, surface reflectance, and detector noise. A modest-size lidar instrument with 0.45 W average laser power and 0.55 m telescope diameter on a 506 km orbit could provide 50-km averaged methane column measurement along the sub-satellite track with a precision of about 1 % over vegetation. The use of a methane absorption trough at 1.65 μm improves the near-surface measurement sensitivity and vastly relaxes the wavelength stability requirement that was identified as one of the major technological risks in the pre-phase A studies for A-SCOPE, a space-based IPDA lidar for carbon dioxide at the European Space Agency. Minimal humidity and temperature sensitivity at this wavelength position will enable accurate measurements in tropical wetlands, key regions with largely uncertain methane emissions. In contrast to actual passive remote sensors, measurements in Polar Regions will be possible and biases due to aerosol layers and thin ice clouds will be minimised.

Comparison of alternate fuels for aircraft. [liquid hydrogen, liquid methane, and synthetic aviation kerosene

NASA Technical Reports Server (NTRS)

Witcofski, R. D.

1979-01-01

Liquid hydrogen, liquid methane, and synthetic aviation kerosene were assessed as alternate fuels for aircraft in terms of cost, capital requirements, and energy resource utilization. Fuel transmission and airport storage and distribution facilities are considered. Environmental emissions and safety aspects of fuel selection are discussed and detailed descriptions of various fuel production and liquefaction processes are given. Technological deficiencies are identified.

Microwave Hydrogen Production from Methane

DTIC Science & Technology

2012-04-01

combustion NOx control of reciprocating engine exhaust and fuel cell application of biogas . Our target is to obtain the methane conversion efficiency...demonstration of MW technology removing and destroying hydrogen sulfide (H2S) and siloxanes from biogas produced by Sacramento Regional Wastewater...running on biogas and is currently conducting the field demonstration of the unit at Tollenaar Dairy in Elk Grove, CA. SMUD, California Air Resources

Reducing Open Cell Landfill Methane Emissions with a Bioactive Alternative Daily

DOE Office of Scientific and Technical Information (OSTI.GOV)

Helene Hilger; James Oliver; Jean Bogner

2009-03-31

Methane and carbon dioxide are formed in landfills as wastes degrade. Molecule-for-molecule, methane is about 20 times more potent than carbon dioxide at trapping heat in the earth's atmosphere, and thus, it is the methane emissions from landfills that are scrutinized. For example, if emissions composed of 60% methane and 40% carbon dioxide were changed to a mix that was 40% methane and 60% carbon dioxide, a 30% reduction in the landfill's global warming potential would result. A 10% methane, 90% carbon dioxide ratio will result in a 75% reduction in global warming potential compared to the baseline. Gas collectionmore » from a closed landfill can reduce emissions, and it is sometimes combined with a biocover, an engineered system where methane oxidizing bacteria living in a medium such as compost, convert landfill methane to carbon dioxide and water. Although methane oxidizing bacteria merely convert one greenhouse gas (methane) to another (carbon dioxide), this conversion can offer significant reductions in the overall greenhouse gas contribution, or global warming potential, associated with the landfill. What has not been addressed to date is the fact that methane can also escape from a landfill when the active cell is being filled with waste. Federal regulations require that newly deposited solid waste to be covered daily with a 6 in layer of soil or an alternative daily cover (ADC), such as a canvas tarp. The aim of this study was to assess the feasibility of immobilizing methane oxidizing bacteria into a tarp-like matrix that could be used for alternative daily cover at open landfill cells to prevent methane emissions. A unique method of isolating methanotrophs from landfill cover soil was used to create a liquid culture of mixed methanotrophs. A variety of prospective immobilization techniques were used to affix the bacteria in a tarp-like matrix. Both gel encapsulation of methanotrophs and gels with liquid cores containing methanotrophs were readily made but prone to rapid desiccation. Bacterial adsorption onto foam padding, natural sponge, and geotextile was successful. The most important factor for success appeared to be water holding capacity. Prototype biotarps made with geotextiles plus adsorbed methane oxidizing bacteria were tested for their responses to temperature, intermittent starvation, and washing (to simulate rainfall). The prototypes were mesophilic, and methane oxidation activity remained strong after one cycle of starvation but then declined with repeated cycles. Many of the cells detached with vigorous washing, but at least 30% appeared resistant to sloughing. While laboratory landfill simulations showed that four-layer composite biotarps made with two different types of geotextile could remove up to 50% of influent methane introduced at a flux rate of 22 g m{sup -2} d{sup -1}, field experiments did not yield high activity levels. Tests revealed that there were high hour-to-hour flux variations in the field, which, together with frequent rainfall events, confounded the field testing. Overall, the findings suggest that a methanotroph embedded biotarp appears to be a feasible strategy to mitigate methane emission from landfill cells, although the performance of field-tested biotarps was not robust here. Tarps will likely be best suited for spring and summer use, although the methane oxidizer population may be able to shift and adapt to lower temperatures. The starvation cycling of the tarp may require the capacity for intermittent reinoculation of the cells, although it is also possible that a subpopulation will adapt to the cycling and become dominant. Rainfall is not expected to be a major factor, because a baseline biofilm will be present to repopulate the tarp. If strong performance can be achieved and documented, the biotarp concept could be extended to include interception of other compounds beyond methane, such as volatile aromatic hydrocarbons and chlorinated solvents.« less

The carbon footprint of integrated milk production and renewable energy systems - A case study.

PubMed

Vida, Elisabetta; Tedesco, Doriana Eurosia Angela

2017-12-31

Dairy farms have been widely acknowledged as a source of greenhouse gas (GHG) emissions. The need for a more environmentally friendly milk production system will likely be important going forward. Whereas methane (CH 4 ) enteric emissions can only be reduced to a limited extent, CH 4 manure emissions can be reduced by implementing mitigation strategies, such as the use of an anaerobic digestion (AD). Furthermore, implementing a photovoltaic (PV) electricity generation system could mitigate the fossil fuels used to cover the electrical needs of farms. In the present study to detect the main environmental hotspots of milk production, a Life Cycle Assessment was adopted to build the Life Cycle Inventory according to ISO 14040 and 14044 in a conventional dairy farm (1368 animals) provided by AD and PV systems. The Intergovernmental Panel on Climate Change tiered approach was adopted to associate the level of emission with each item in the life cycle inventory. The functional unit refers to 1kg of fat-and-protein-corrected-milk (FPCM). In addition to milk products, other important co-products need to be considered: meat and renewable energy production from AD and PV systems. A physical allocation was applied to attribute GHG emissions among milk and meat products. Renewable energy production from AD and PV systems was considered, discounting carbon credits due to lower CH 4 manure emissions and to the minor exploitation of fossil energy. The CF of this farm scenario was 1.11kg CO 2 eq/kg FPCM. The inclusion of AD allowed for the reduction of GHG emissions from milk production by 0.26kg CO 2 eq/kg FPCM. The PV system contribution was negligible due to the small dimensions of the technology. The results obtained in this study confirm that integrating milk production with other co-products, originated from more efficient manure management, is a successful strategy to mitigate the environmental impact of dairy production. Copyright © 2017 Elsevier B.V. All rights reserved.

[Evaluation indices of greenhouse gas mitigation technologies in cropland ecosystem].

PubMed

Li, Jian-zheng; Wang, Ying-chun; Wang, Li-gang; Li, Hu; Qiu, Jian-jun; Wang, Dao-long

2015-01-01

In spite of the increasing studies on greenhouse gas (GHG) emissions mitigation technologies, there is still a lack of systematic indices for evaluation of their overall impacts in croplands. In this study, we collected all the indices relating to greenhouse gas emissions and analyzed each index following the principles of representativeness, objectivity, completeness, dominance and operability. Finally, we proposed evaluation indices for mitigation technologies based on the current situation of China. Crop yield per unit area was proposed as a constrained index, and greenhouse gas emissions intensity, defined as GHG emissions per unit of produced yield, was proposed as comprehensive index to evaluate the greenhouse effect of various croplands mitigation technologies. Calculation of GHG emissions intensity involved yield, change of soil organic carbon, direct N2O emissions, paddy CH4 emissions and direct and indirect emissions from inputs into croplands. By following these evaluation indices, the greenhouse effect of the technologies could be well evaluated, which could provide scientific basis for their further adoption.

Methane Seepage on Mars: Where to Look and Why

NASA Astrophysics Data System (ADS)

Oehler, Dorothy Z.; Etiope, Giuseppe

2017-12-01

Methane on Mars is a topic of special interest because of its potential association with microbial life. The variable detections of methane by the Curiosity rover, orbiters, and terrestrial telescopes, coupled with methane's short lifetime in the martian atmosphere, may imply an active gas source in the planet's subsurface, with migration and surface emission processes similar to those known on Earth as "gas seepage." Here, we review the variety of subsurface processes that could result in methane seepage on Mars. Such methane could originate from abiotic chemical reactions, thermogenic alteration of abiotic or biotic organic matter, and ancient or extant microbial metabolism. These processes can occur over a wide range of temperatures, in both sedimentary and igneous rocks, and together they enhance the possibility that significant amounts of methane could have formed on early Mars. Methane seepage to the surface would occur preferentially along faults and fractures, through focused macro-seeps and/or diffuse microseepage exhalations. Our work highlights the types of features on Mars that could be associated with methane release, including mud-volcano-like mounds in Acidalia or Utopia; proposed ancient springs in Gusev Crater, Arabia Terra, and Valles Marineris; and rims of large impact craters. These could have been locations of past macro-seeps and may still emit methane today. Microseepage could occur through faults along the dichotomy or fractures such as those at Nili Fossae, Cerberus Fossae, the Argyre impact, and those produced in serpentinized rocks. Martian microseepage would be extremely difficult to detect remotely yet could constitute a significant gas source. We emphasize that the most definitive detection of methane seepage from different release candidates would be best provided by measurements performed in the ground or at the ground-atmosphere interface by landers or rovers and that the technology for such detection is currently available.

Net mitigation potential of straw return to Chinese cropland: estimation with a full greenhouse gas budget model.

PubMed

Lu, Fei; Wang, Xiaoke; Han, Bing; Ouyang, Zhiyun; Duan, Xiaonan; Zheng, Hua

2010-04-01

Based on the carbon-nitrogen cycles and greenhouse gas (GHG) mitigation and emission processes related to straw return and burning, a compound greenhouse gas budget model, the "Straw Return and Burning Model" (SRBM), was constructed to estimate the net mitigation potential of straw return to the soil in China. As a full GHG budget model, the SRBM addressed the following five processes: (1) soil carbon sequestration, (2) mitigation of synthetic N fertilizer substitution, (3) methane emission from rice paddies, (4) additional fossil fuel use for straw return, and (5) CH4 and N2O emissions from straw burning in the fields. Two comparable scenarios were created to reflect different degrees of implementation for straw return and straw burning. With GHG emissions and mitigation effects of the five processes converted into global warming potential (GWP), the net GHG mitigation was estimated. We concluded that (1) when the full greenhouse gas budget is considered, the net mitigation potential of straw return differs from that when soil carbon sequestration is considered alone; (2) implementation of straw return across a larger area of cropland in 10 provinces (i.e., Shanghai, Jiangsu, Zhejiang, Fujian, Jiangxi, Hubei, Hunan, Guangdong, Guangxi, and Hainan) will increase net GHG emission; (3) if straw return is promoted as a feasible mitigation measure in the remaining provinces, the total net mitigation potential before soil organic carbon (SOC) saturation will be 71.89 Tg CO2 equivalent (eqv)/yr, which is equivalent to 1.733% of the annual carbon emission from fossil fuel use in China in 2003; (4) after SOC saturation, only 13 of 21 provinces retain a relatively small but permanent net mitigation potential, while in the others the net GHG mitigation potential will gradually diminish; and (5) the major obstacle to the feasibility or permanence of straw return as a mitigation measure is the increased CH4 emission from rice paddies. The paper also suggests that comparable scenarios in which all the related carbon-nitrogen cycles are taken into account be created to estimate the mitigation potentials of organic wastes in different utilizations and treatments.

Enteric methane emissions and lactational performance of Holstein cows fed different concentrations of coconut oil.

PubMed

Hollmann, M; Powers, W J; Fogiel, A C; Liesman, J S; Bello, N M; Beede, D K

2012-05-01

To determine if dietary medium-chain fatty acids (FA; C(8) to C(14)) may mitigate enteric methane emissions, 24 cows were blocked by body size (n=2) and randomly assigned to 1 sequence of dietary treatments. Diets were fed for 35 d each in 2 consecutive periods. Diets differed in concentrations of coconut oil (CNO; ~75% medium-chain FA): 0.0 (control) or 1.3, 2.7, or 3.3% CNO, dry matter basis. The control diet contained 50% forage (74% from corn silage), 16.5% crude protein (60% from rumen-degradable protein), 34% neutral detergent fiber (NDF; 71% from forage), and 28% starch, dry matter basis. Data and sample collections were from d 29 to 35 in environmentally controlled rooms to measure methane (CH(4)) production. Methane emitted was computed from the difference in concentrations of inlet and outlet air and flux as measured 8 times per day. Control cows emitted 464 g of CH(4)/d, consumed 22.9 kg of DM/d, and produced 34.8 kg of solids-corrected milk/d and 1.3 kg of milk fat/d. Treatment with 1.3, 2.7, or 3.3% dietary CNO reduced CH(4) (449, 291, and 253 g/d, respectively), but concomitantly depressed dry matter intake (21.4, 17.9, and 16.2 kg/d, respectively), solids-corrected milk yield (36.3, 28.4, and 26.8 kg/d, respectively), and milk fat yield (1.4, 0.9, and 0.9 kg/d, respectively). The amount of NDF digested in the total tract decreased with increased dietary CNO concentrations; thus, CH(4) emitted per unit of NDF digested rose from 118 to 128, 153, and 166 g/kg across CNO treatments. Dietary CNO did not significantly affect apparent digestibility of CP but increased apparent starch digestibility from 92 to 95%. No FA C(10) or shorter were detected in feces, and apparent digestibility decreased with increasing FA chain length. Coconut oil concentrations of 2.7 or 3.3% decreased yields of milk FA C(14). The highest milk fat concentration (3.69%; 1.3% CNO) was due to the greatest yields of C(12) to C(16) milk FA. Milk FA concentrations of C(18:2 trans-10,cis-12) were related to increased dietary CNO concentrations and presumably to depressed ruminal NDF digestion. Moderate dietary CNO concentrations (e.g., 1.3%) may benefit lactational performance; however, CNO concentrations greater than or equal to 2.7% depressed dry matter intake, milk yield, milk fat yield, and NDF utilization. If mitigation of enteric CH(4) emissions is due to decreased digestion of dietary NDF, then this will lessen a major advantage of ruminants compared with nonruminants in food-production systems. Thus, CNO has limited use for enteric CH(4) mitigation in lactating dairy cows. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Integrated Pressure-Fed Liquid Oxygen / Methane Propulsion Systems - Morpheus Experience, MARE, and Future Applications

NASA Technical Reports Server (NTRS)

Hurlbert, Eric; Morehead, Robert; Melcher, John C.; Atwell, Matt

2016-01-01

An integrated liquid oxygen (LOx) and methane propulsion system where common propellants are fed to the reaction control system and main engines offers advantages in performance, simplicity, reliability, and reusability. LOx/Methane provides new capabilities to use propellants that are manufactured on the Mars surface for ascent return and to integrate with power and life support systems. The clean burning, non-toxic, high vapor pressure propellants provide significant advantages for reliable ignition in a space vacuum, and for reliable safing or purging of a space-based vehicle. The NASA Advanced Exploration Systems (AES) Morpheus lander demonstrated many of these key attributes as it completed over 65 tests including 15 flights through 2014. Morpheus is a prototype of LOx/Methane propellant lander vehicle with a fully integrated propulsion system. The Morpheus lander flight demonstrations led to the proposal to use LOx/Methane for a Discovery class mission, named Moon Aging Regolith Experiment (MARE) to land an in-situ science payload for Southwest Research Institute on the Lunar surface. Lox/Methane is extensible to human spacecraft for many transportation elements of a Mars architecture. This paper discusses LOx/Methane propulsion systems in regards to trade studies, the Morpheus project experience, the MARE NAVIS (NASA Autonomous Vehicle for In-situ Science) lander, and future possible applications. The paper also discusses technology research and development needs for Lox/Methane propulsion systems.

Enhanced activity and stability of La-doped CeO2 monolithic catalysts for lean-oxygen methane combustion.

PubMed

Zhu, Wenjun; Jin, Jianhui; Chen, Xiao; Li, Chuang; Wang, Tonghua; Tsang, Chi-Wing; Liang, Changhai

2018-02-01

Effective utilization of coal bed methane is very significant for energy utilization and environment protection. Catalytic combustion of methane is a promising way to eliminate trace amounts of oxygen in the coal bed methane and the key to this technology is the development of high-efficiency catalysts. Herein, we report a series of Ce 1-x La x O 2-δ (x = 0-0.8) monolithic catalysts for the catalytic combustion of methane, which are prepared by citric acid method. The structural characterization shows that the substitution of La enhance the oxygen vacancy concentration and reducibility of the supports and promote the migration of the surface oxygen, as a result improve the catalytic activity of CeO 2 . M-Ce 0.8 La 0.2 O 2-δ (monolithic catalyst, Ce 0.8 La 0.2 O 2-δ coated on cordierite honeycomb) exhibits outstanding activity for methane combustion, and the temperature for 10 and 90% methane conversion are 495 and 580 °C, respectively. Additionally, Ce 0.8 La 0.2 O 2-δ monolithic catalyst presents excellent stability at high temperature. These Ce 1-x La x O 2-δ monolithic materials with a small amount of La incorporation therefore show promises as highly efficient solid solution catalysts for lean-oxygen methane combustion. Graphical abstract ᅟ.

High performance biological methanation in a thermophilic anaerobic trickle bed reactor.

PubMed

Strübing, Dietmar; Huber, Bettina; Lebuhn, Michael; Drewes, Jörg E; Koch, Konrad

2017-12-01

In order to enhance energy efficiency of biological methanation of CO 2 and H 2 , this study investigated the performance of a thermophilic (55°C) anaerobic trickle bed reactor (ATBR) (58.1L) at ambient pressure. With a methane production rate of up to 15.4m 3 CH4 /(m 3 trickle bed ·d) at methane concentrations above 98%, the ATBR can easily compete with the performance of other mixed culture methanation reactors. Control of pH and nutrient supply turned out to be crucial for stable operation and was affected significantly by dilution due to metabolic water production, especially during demand-orientated operation. Considering practical applications, inoculation with digested sludge, containing a diverse biocenosis, showed high adaptive capacity due to intrinsic biological diversity. However, no macroscopic biofilm formation was observed at thermophilic conditions even after 313days of operation. The applied approach illustrates the high potential of thermophilic ATBRs as a very efficient energy conversion and storage technology. Copyright © 2017 Elsevier Ltd. All rights reserved.

Methane Post-Processing and Hydrogen Separation for Spacecraft Oxygen Loop Closure

NASA Technical Reports Server (NTRS)

Greenwood, Zachary W.; Abeny, Morgan B.; Wall, Terry; Miller, Lee A.; Wheeler, Richard R., Jr.

2017-01-01

State-of-the-art life support oxygen recovery technology on the International Space Station is based on the Sabatier reaction where only about half of the oxygen required for the crew is recovered from metabolic carbon dioxide (CO2). The Sabatier reaction produces water as the primary product and methane as a byproduct. Oxygen recovery is constrained by both the limited availability of reactant hydrogen from water electrolysis and Sabatier methane (CH4) being vented as a waste product resulting in a continuous loss of reactant hydrogen. Post-processing methane with the Plasma Pyrolysis Assembly (PPA) to recover this hydrogen has the potential to substantially increase oxygen recovery and thus dramatically reduce the logistical challenges associated with oxygen resupply. The PPA decomposes methane into predominantly hydrogen and acetylene. A purification system is necessary to purify hydrogen before it is recycled back to the Sabatier reactor. Testing and evaluation of acetylene removal systems and PPA system architectures are presented and discussed.

Indian oil company joins efforts to reduce methane emissions

NASA Astrophysics Data System (ADS)

Kumar, Mohi

The Oil and Natural Gas Corp, Ltd. (ONGC), headquartered in Dehradun, India, has joined seven U.S. and Canadian oil and natural gas companies as a partner in a U.S. Environmental Protection Agency program to reduce greenhouse gas emissions. EPA's Natural Gas STAR International Program aims to reduce methane emissions from the oil and natural gas sector while delivering more gas to markets around the world. With this partnership, ONGC agrees to implement emissions reduction practices and to submit annual reports on progress achieved; EPA agrees to assist ONGC with training technicians in new cost-effective technologies that will help achieve target emissions. The Natural Gas STAR International Program is administered under the Methane to Markets Partnership, a group of 20 countries and 600 companies across the globe that since 2004 has volunteered to cut methane emissions. More information on EPA's agreement with ONGC can be found at http://www.epa.gov/gasstar/index.htm; information about the Methane to Markets Partnership can be found at http://www.methanetomarkets.org.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grigg, Reid; McPherson, Brian; Lee, Rober

The Southwest Regional Partnership on Carbon Sequestration (SWP) one of seven regional partnerships sponsored by the U.S. Department of Energy (USDOE) carried out five field pilot tests in its Phase II Carbon Sequestration Demonstration effort, to validate the most promising sequestration technologies and infrastructure concepts, including three geologic pilot tests and two terrestrial pilot programs. This field testing demonstrated the efficacy of proposed sequestration technologies to reduce or offset greenhouse gas emissions in the region. Risk mitigation, optimization of monitoring, verification, and accounting (MVA) protocols, and effective outreach and communication were additional critical goals of these field validation tests. Themore » program included geologic pilot tests located in Utah, New Mexico, Texas, and a region-wide terrestrial analysis. Each geologic sequestration test site was intended to include injection of a minimum of ~75,000 tons/year CO{sub 2}, with minimum injection duration of one year. These pilots represent medium- scale validation tests in sinks that host capacity for possible larger-scale sequestration operations in the future. These validation tests also demonstrated a broad variety of carbon sink targets and multiple value-added benefits, including testing of enhanced oil recovery and sequestration, enhanced coalbed methane production and a geologic sequestration test combined with a local terrestrial sequestration pilot. A regional terrestrial sequestration demonstration was also carried out, with a focus on improved terrestrial MVA methods and reporting approaches specific for the Southwest region.« less

Development of Tandem, Double-Focusing, Electron Impact, Gas Source Mass Spectrometer for Measurement of Rare Double-Substituted Isotoplogues in Geochemistry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Young, Edward D.

This project culminated in construction and delivery of the world’s first large-radius gas-source isotope ratio mass spectrometer that permits unparalleled analyses of the stable isotopic composition of methane gas. The instrument, referred to as the “Panorama” and installed at UCLA in March 2015, can now be used to determine the relative abundances of rare isotopic species of methane that serve as tracers of temperature of formation and/or subsequent processing of gas. With this technology we can begin to delineate different sources and sinks of methane isotopically in ways not possible until now.

A review on the applications of microbial electrolysis cells in anaerobic digestion.

PubMed

Yu, Zhengsheng; Leng, Xiaoyun; Zhao, Shuai; Ji, Jing; Zhou, Tuoyu; Khan, Aman; Kakde, Apurva; Liu, Pu; Li, Xiangkai

2018-05-01

Anaerobic digestion (AD) has been widely used for biogas or biofuel generation from waste treatment. Because a low production rate and instability of AD occur frequently, various technologies have been applied to improvement of AD. Microbial electrolysis cells (MECs), an emerging technology, can convert organic matter into hydrogen, methane, and other value-added products. Recent studies showed that application of MEC to AD (MEC-AD) can accelerate degradation of a substrate (including recalcitrant compounds) and alter AD microbial community by enriching exoelectrogens and methanogens thus increasing biogas production. With stable microbial communities established, improvement of MEC-AD for methane production was achieved. MEC-AD process can be monitored in real-time by detecting electric signals, which linearly correlate with substrate concentrations. This review attempts to evaluate interactions among the decomposition of substrates, MEC-AD system, and the microbial community. This analysis should provide useful insights into the improvement of methane production and the performance of MEC-AD. Copyright © 2018 Elsevier Ltd. All rights reserved.

Regeneratively Cooled Liquid Oxygen/Methane Technology Development

NASA Technical Reports Server (NTRS)

Robinson, Joel W.; Greene, Christopher B.; Stout, Jeffrey

2012-01-01

The National Aeronautics & Space Administration (NASA) has identified Liquid Oxygen (LOX)/Liquid Methane (LCH4) as a potential propellant combination for future space vehicles based upon exploration studies. The technology is estimated to have higher performance and lower overall systems mass compared to existing hypergolic propulsion systems. NASA-Marshall Space Flight Center (MSFC) in concert with industry partner Pratt & Whitney Rocketdyne (PWR) utilized a Space Act Agreement to test an oxygen/methane engine system in the Summer of 2010. PWR provided a 5,500 lbf (24,465 N) LOX/LCH4 regenerative cycle engine to demonstrate advanced thrust chamber assembly hardware and to evaluate the performance characteristics of the system. The chamber designs offered alternatives to traditional regenerative engine designs with improvements in cost and/or performance. MSFC provided the test stand, consumables and test personnel. The hot fire testing explored the effective cooling of one of the thrust chamber designs along with determining the combustion efficiency with variations of pressure and mixture ratio. The paper will summarize the status of these efforts.

Economic and environmental sustainability of an AnMBR treating urban wastewater and organic fraction of municipal solid waste.

PubMed

Pretel, R; Moñino, P; Robles, A; Ruano, M V; Seco, A; Ferrer, J

2016-09-01

The objective of this study was to evaluate the economic and environmental sustainability of a submerged anaerobic membrane bioreactor (AnMBR) treating urban wastewater (UWW) and organic fraction of municipal solid waste (OFMSW) at ambient temperature in mild/hot climates. To this aim, power requirements, energy recovery from methane (biogas methane and methane dissolved in the effluent), consumption of reagents for membrane cleaning, and sludge handling (polyelectrolyte and energy consumption) and disposal (farmland, landfilling and incineration) were evaluated within different operating scenarios. Results showed that, for the operating conditions considered in this study, AnMBR technology is likely to be a net energy producer, resulting in considerable cost savings (up to €0.023 per m(3) of treated water) when treating low-sulphate influent. Life cycle analysis (LCA) results revealed that operating at high sludge retention times (70 days) and treating UWW jointly with OFMSW enhances the overall environmental performance of AnMBR technology. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biogas energy production from tropical biomass wastes by anaerobic digestion.

PubMed

Ge, Xumeng; Matsumoto, Tracie; Keith, Lisa; Li, Yebo

2014-10-01

Anaerobic digestion (AD) is an attractive technology in tropical regions for converting locally abundant biomass wastes into biogas which can be used to produce heat, electricity, and transportation fuels. However, investigations on AD of tropical forestry wastes, such as albizia biomass and food wastes, such as taro, papaya, and sweet potato, are limited. In this study, these tropical biomass wastes were evaluated for biogas production by liquid AD (L-AD) and/or solid-state AD (SS-AD), depending on feedstock characteristics. When albizia leaves and chips were used as feedstocks, L-AD had greater methane yields (161 and 113 L kg(-1)VS, respectively) than SS-AD (156.8 and 59.6 L kg(-1)VS, respectively), while SS-AD achieved 5-fold higher volumetric methane productivity than L-AD. Mono-digestion and co-digestion of taro skin, taro flesh, papaya, and sweet potato achieved methane yields from 345 to 411 L kg(-1)VS, indicating the robustness of AD technology. Copyright © 2014 Elsevier Ltd. All rights reserved.

Performance and fouling characteristics of a submerged anaerobic membrane bioreactor for kraft evaporator condensate treatment.

PubMed

Xie, K; Lin, H J; Mahendran, B; Bagley, D M; Leung, K T; Liss, S N; Liao, B Q

2010-04-14

Submerged anaerobic membrane bioreactor (SAnMBR) technology was studied for kraft evaporator condensate treatment at 37 +/- 1 degrees C over a period of 9 months. Under tested organic loading rates of 1-24 kg COD/m3/day, a chemical oxygen demand (COD) removal efficiency of 93-99% was achieved with a methane production rate of 0.35 +/- 0.05 L methane/g COD removed and a methane content of 80-90% in produced biogas. Bubbling of recycled biogas was effective for in-situ membrane cleaning, depending on the biogas sparging rate used. The membrane critical flux increased and the membrane fouling rate decreased with an increase in the biogas sparging rate. The scanning electron microscopy images showed membrane pore clogging was not significant and sludge cake formation on the membrane surface was the dominant mechanism of membrane fouling. The results suggest that the SAnMBR is a promising technology for energy recovery from kraft evaporator condensate.

Effects of diet forage source and neutral detergent fiber content on milk production of dairy cattle and methane emissions determined using GreenFeed and respiration chamber techniques.

PubMed

Hammond, K J; Jones, A K; Humphries, D J; Crompton, L A; Reynolds, C K

2016-10-01

Strategies to mitigate greenhouse gas emissions from dairy cattle are unlikely to be adopted if production or profitability is reduced. The primary objective of this study was to examine the effects of high maize silage (MS) versus high grass silage (GS) diets, without or with added neutral detergent fiber (NDF) on milk production and methane emission of dairy cattle, using GreenFeed (GF) or respiration chamber (RC) techniques for methane emission measurements. Experiment 1 was 12wk in duration with a randomized block continuous design and 40 Holstein cows (74d in milk) in free-stall housing, assigned to 1 of 4 dietary treatments (n=10 per treatment), according to calving date, parity, and milk yield. Milk production and dry matter intake (DMI) were measured daily, and milk composition measured weekly, with methane yield (g/kg of DMI) estimated using a GF unit (wk 10 to 12). Experiment 2 was a 4×4 Latin square design with 5-wk periods and 4 dairy cows (114d in milk) fed the same 4 dietary treatments as in experiment 1. Measurements of DMI, milk production, and milk composition occurred in wk 4, and DMI, milk production, and methane yield were measured for 2d in RC during wk 5. Dietary treatments for both experiments were fed as total mixed rations offered ad libitum and containing 500g of silage/kg of dry matter composed (DM basis) of either 75:25 MS:GS (MS) or 25:75 MS:GS (GS), without or with added NDF from chopped straw and soy hulls (+47g of NDF/kg of dry matter). In both experiments, compared with high GS, cows fed high MS had a higher DMI, greater milk production, and lower methane yield (24% lower in experiment 1 using GF and 8% lower in experiment 2 using RC). Added NDF increased (or tended to increase) methane yield for high MS, but not high GS diets. In the separate experiments, the GF and RC methods detected similar dietary treatment effects on methane emission (expressed as g/d and g/kg of DMI), although the magnitude of the differences varied between experiments. Overall methane emission and yield were 448g/d and 20.9g/kg of DMI for experiment 1 using GF and 458g/d and 23.8g/kg of DMI for experiment 2 using RC, respectively. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Wheat is more potent than corn or barley for dietary mitigation of enteric methane emissions from dairy cows.

PubMed

Moate, P J; Williams, S R O; Jacobs, J L; Hannah, M C; Beauchemin, K A; Eckard, R J; Wales, W J

2017-09-01

Wheat is the most common concentrate fed to dairy cows in Australia, but few studies have examined the effects of wheat feeding on enteric methane emissions, and no studies have compared the relative potencies of wheat, corn, and barley for their effects on enteric methane production. In this 35-d experiment, 32 Holstein dairy cows were offered 1 of 4 diets: a corn diet (CRN) of 10.0 kg of dry matter (DM)/d of single-rolled corn grain, 1.8 kg of DM/d of canola meal, 0.2 kg of DM/d of minerals, and 11.0 kg of DM/d of chopped alfalfa hay; a wheat diet (WHT) similar to the CRN diet but with the corn replaced by single-rolled wheat; a barley diet (SRB) similar to the CRN diet but with the corn replaced by single-rolled barley; and a barley diet (DRB) similar to the CRN diet but with the corn replaced by double-rolled barley. Individual cow feed intakes, milk yields, and milk compositions were measured daily but reported for the last 5 d of the experiment. During the last 5 d of the experiment, individual cow methane emissions were measured using the SF 6 tracer technique for all cows, and ruminal fluid pH was continuously measured by intraruminal sensors for 3 cows in each treatment group. The average DM intake of cows offered the CRN, WHT, SRB, and DRB diets was 22.2, 21.1, 22.6, and 22.6 kg/d. The mean energy-corrected milk of cows fed the WHT diet was less than that of cows fed the other diets. This occurred because the milk fat percentage of cows fed the WHT diet was significantly less than that of cows fed the other diets. The mean methane emissions and methane yields of cows fed the WHT diet were also significantly less than those of cows fed the other diets. Indeed, the CRN, SRB, and DRB diets were associated with 49, 73, and 78% greater methane emissions, respectively, compared with the emissions from the WHT diet. Methane yield was found to be most strongly related to the minimum daily ruminal fluid pH. This study showed that although the inclusion of wheat in the diet of dairy cows could be an effective strategy for substantially reducing their methane emissions, it also reduced their milk fat percentage and production of milk fat and energy-corrected milk. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Conversion of Methane into Methanol and Ethanol over Nickel Oxide on Ceria-Zirconia Catalysts in a Single Reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Okolie, Chukwuemeka; Belhseine, Yasmeen F.; Lyu, Yimeng

Direct conversion of methane into alcohols is a promising technology for converting stranded methane reserves into liquids that can be transported in pipelines and upgraded to value-added chemicals. We demonstrate that a catalyst consisting of small nickel oxide clusters supported on ceria-zirconia (NiO/CZ) can selectively oxidize methane to methanol and ethanol in a single, steady-state process at 723 K using O2 as an abundantly available oxidant. The presence of steam is required to obtain alcohols rather than CO2 as the product of catalytic combustion. The unusual activity of this catalyst is attributed to the synergy between the small Lewis acidicmore » NiO clusters and the redox-active CZ support, which also stabilizes the small NiO clusters.« less

Conversion of Methane to Methanol and Ethanol over Nickel Oxide on Ceria-Zirconia Catalysts in a Single Reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Okolie, Chukwuemeka; Belhseine, Yasmeen F.; Lyu, Yimeng

Here, the conversion of methane into alcohols under moderate reaction conditions is a promising technology for converting stranded methane reserves into liquids that can be transported in pipelines and upgraded to value-added chemicals. We demonstrate that a catalyst consisting of small nickel oxide clusters supported on ceria-zirconia (NiO/CZ) can convert methane to methanol and ethanol in a single, steady-state process at 723 K using O 2 as an abundantly available oxidant. The presence of steam is required to obtain alcohols rather than CO 2 as the product of catalytic combustion. The unusual activity of this catalyst is attributed to themore » synergy between the small Lewis acidic NiO clusters and the redox-active CZ support, which also stabilizes the small NiO clusters.« less

Conversion of Methane to Methanol and Ethanol over Nickel Oxide on Ceria-Zirconia Catalysts in a Single Reactor

DOE PAGES

Okolie, Chukwuemeka; Belhseine, Yasmeen F.; Lyu, Yimeng; ...

2017-08-08

Here, the conversion of methane into alcohols under moderate reaction conditions is a promising technology for converting stranded methane reserves into liquids that can be transported in pipelines and upgraded to value-added chemicals. We demonstrate that a catalyst consisting of small nickel oxide clusters supported on ceria-zirconia (NiO/CZ) can convert methane to methanol and ethanol in a single, steady-state process at 723 K using O 2 as an abundantly available oxidant. The presence of steam is required to obtain alcohols rather than CO 2 as the product of catalytic combustion. The unusual activity of this catalyst is attributed to themore » synergy between the small Lewis acidic NiO clusters and the redox-active CZ support, which also stabilizes the small NiO clusters.« less

Influence of methane emissions and vehicle efficiency on the climate implications of heavy-duty natural gas trucks.

PubMed

Camuzeaux, Jonathan R; Alvarez, Ramón A; Brooks, Susanne A; Browne, Joshua B; Sterner, Thomas

2015-06-02

While natural gas produces lower carbon dioxide emissions than diesel during combustion, if enough methane is emitted across the fuel cycle, then switching a heavy-duty truck fleet from diesel to natural gas can produce net climate damages (more radiative forcing) for decades. Using the Technology Warming Potential methodology, we assess the climate implications of a diesel to natural gas switch in heavy-duty trucks. We consider spark ignition (SI) and high-pressure direct injection (HPDI) natural gas engines and compressed and liquefied natural gas. Given uncertainty surrounding several key assumptions and the potential for technology to evolve, results are evaluated for a range of inputs for well-to-pump natural gas loss rates, vehicle efficiency, and pump-to-wheels (in-use) methane emissions. Using reference case assumptions reflecting currently available data, we find that converting heavy-duty truck fleets leads to damages to the climate for several decades: around 70-90 years for the SI cases, and 50 years for the more efficient HPDI. Our range of results indicates that these fuel switches have the potential to produce climate benefits on all time frames, but combinations of significant well-to-wheels methane emissions reductions and natural gas vehicle efficiency improvements would be required.

Feasibility tests for treating shampoo and hair colorant wastewaters using anaerobic processes.

PubMed

Ahammad, Shaikh Z; Yakubu, A; Dolfing, J; Mota, C; Graham, D W

2012-01-01

Wastes from the personal care product (PCP) industry are often high in biodegradable carbon, which makes them amenable to aerobic biological treatment, although process costs are usually high due to aeration inefficiencies, high electricity demand and production of large amounts of sludge. As such, anaerobic treatment technologies are being considered to lower net energy costs by reducing air use and increasing methane production. To assess the amenability of PCP wastes to anaerobic treatment, methane yields and rates were quantified in different anaerobic reactors treating typical PCP wastes, including wastes from shampoo and hair colorant products. Overall, shampoo wastes were more amenable to methanogenesis with almost double the methane yields compared with colour wastes. To assess relevant microbial guilds, qPCR was performed on reactor biomass samples. Methanosaetaceae abundances were always significantly higher than Methanosarcinaceae and Methanomicrobiales abundances (P < 0.05), and did not differ significantly between waste types. Although colour wastes were less amenable to anaerobic treatment than shampoo wastes, differences cannot be explained by relative microbial abundances and probably result from the presence of inhibiting compounds in hair colorants (e.g., oxidants) at higher levels. Results showed that anaerobic technologies have great potential for treating PCP wastes, but additional work is needed to establish the basis of elevated methane yields and inhibition, especially when colorant wastes are present.

Creating Methane from Plastics: Recycling at a Lunar Outpost

NASA Technical Reports Server (NTRS)

Captain, Janine; Santiago, Eddie; Wheeler, Ray; Strayer, RIchard; Garland, Jay; Parrish, Clyde

2010-01-01

The high cost of re-supply from Earth demands resources to be utilized to the fullest extent for exploration missions. Recycling is a key technology that maximizes the available resources by converting waste products into useful commodities. One example of this is to convert crew member waste such as plastic packaging, food scraps, and human waste, into fuel. The ability to refuel on the lunar surface would reduce the vehicle mass during launch and provide excess payload capability. The goal of this project is to determine the feasibility of recycling waste into methane on the lunar outpost by performing engineering assessments and lab demonstrations of the technology. The first goal of the project was to determine how recycling could influence lunar exploration. Table I shows an estimation of the typical dried waste stream generated each day for a crew of four. Packaging waste accounts for nearly 86% of the dry waste stream and is a significant source of carbon on the lunar surface. This is important because methane (CH4) can be used as fuel and no other source of carbon is available on the lunar surface. With the initial assessment indicating there is sufficient resources in the waste stream to provide refueling capabilities, the project was designed to examine the conversion of plastics into methane.

Review of Mitigation Costs for Stabilizing Greenhouse Gas Concentrations

NASA Astrophysics Data System (ADS)

van Ruijven, B. J.; O'Neill, B. C.

2014-12-01

Mitigation of greenhouse gas emissions to avoid future climate change comes at a cost, because low-emission technologies are more expensive than GHG-emitting technology options. The increase in mitigation cost is not linearly related to the stabilization level, though: the first emission reductions are relatively cheap, but deeper emission reductions become more expensive. Therefore, emission reduction to medium levels of GHG concentrations , such as 4.5 or 6 W/m2, is considerably cheaper than emission reduction to low levels of GHG concentrations, such as 2.6 or 3.7 W/m2. Moreover, mitigation costs are influenced by many other aspects than the targeted mitigation level alone, such as whether or not certain technologies are available or societally acceptable (Kriegler et al., 2014); the rate of technological progress and cost reduction of low-emission technologies; the level of final energy demand (Riahi et al., 2011), and the level of global cooperation and trade in emission allowances (den Elzen and Höhne, 2010). This paper reviews the existing literature on greenhouse gas mitigation costs. We analyze the available data on mitigation costs and draw conclusions on how these change for different stabilization levels of GHG concentrations. We will take into account the aspects of technology, energy demand, and cooperation in distinguishing differences between scenarios and stabilization levels. References: den Elzen, M., Höhne, N., 2010. Sharing the reduction effort to limit global warming to 2C. Climate Policy 10, 247-260. Kriegler, E., Weyant, J., Blanford, G., Krey, V., Clarke, L., Edmonds, J., Fawcett, A., Luderer, G., Riahi, K., Richels, R., Rose, S., Tavoni, M., Vuuren, D., 2014. The role of technology for achieving climate policy objectives: overview of the EMF 27 study on global technology and climate policy strategies. Climatic Change, 1-15. Riahi, K., Dentener, F., Gielen, D., Grubler, A., Jewell, J., Klimont, Z., Krey, V., McCollum, D., Pachauri, S., Rao, S., van Ruijven, B., van Vuuren, D.P., Wilson, C., 2011. Energy Pathways for Sustainable Development, The Global Energy Assessment: Toward a More Sustainable Future. IIASA, Laxenburg, Austria and Cambridge University Press, Cambridge, UK.

Foundational Methane Propulsion Related Technology Efforts, and Challenges for Applications to Human Exploration Beyond Earth Orbit

NASA Technical Reports Server (NTRS)

Brown, Thomas; Klem, Mark; McRight, Patrick

2016-01-01

Current interest in human exploration beyond earth orbit is driving requirements for high performance, long duration space transportation capabilities. Continued advancement in photovoltaic power systems and investments in high performance electric propulsion promise to enable solar electric options for cargo delivery and pre-deployment of operational architecture elements. However, higher thrust options are required for human in-space transportation as well as planetary descent and ascent functions. While high thrust requirements for interplanetary transportation may be provided by chemical or nuclear thermal propulsion systems, planetary descent and ascent systems are limited to chemical solutions due to their higher thrust to weight and potential planetary protection concerns. Liquid hydrogen fueled systems provide high specific impulse, but pose challenges due to low propellant density and the thermal issues of long term propellant storage. Liquid methane fueled propulsion is a promising compromise with lower specific impulse, higher bulk propellant density and compatibility with proposed in-situ propellant production concepts. Additionally, some architecture studies have identified the potential for commonality between interplanetary and descent/ascent propulsion solutions using liquid methane (LCH4) and liquid oxygen (LOX) propellants. These commonalities may lead to reduced overall development costs and more affordable exploration architectures. With this increased interest, it is critical to understand the current state of LOX/LCH4 propulsion technology and the remaining challenges to its application to beyond earth orbit human exploration. This paper provides a survey of NASA's past and current methane propulsion related technology efforts, assesses the accomplishments to date, and examines the remaining risks associated with full scale development.

Medicinal herbs as a potential strategy to decrease methane production by rumen microbiota: a systematic evaluation with a focus on Perilla frutescens seed extract.

PubMed

Wang, Jiakun; Liu, Mei; Wu, Yuelei; Wang, Liang; Liu, Jianxin; Jiang, Linshu; Yu, Zhongtang

2016-11-01

Mitigation of the methane (CH 4 ) emission from ruminants is needed to decrease the environmental impact of ruminant animal production. Different plant materials and chemicals have been tested, but few are both effective and practical. Medicinal herbs contain biological compounds and antimicrobials that may be effective in lowering the CH 4 production. However, few studies have systematically evaluated medicinal herbs for their effect on CH 4 production or on the rumen microbiota. In this study, extracts from 100 medicinal herbs were assessed for their ability to decrease CH 4 production by rumen microbiota in vitro. The extracts of 12 herbs effectively lowered the CH 4 production, with the extract of Perilla frutescens seeds being the most effective. The major components of P. frutescens seed extract were identified, and the effects of the extract on the fermentation characteristics and populations of rumen methanogens, fungi, protozoa, and select bacteria were also assessed. The decreased CH 4 production induced by the P. frutescens seed extract was accompanied by an increased abundance of Ruminobacter, Selenomonas, Succinivibrio, Shuttleworthis, Pseudobutyrivbrio, Anaerovibrio, and Roseomonas and a decreased abundance of Methanobrevibacter millerae. The abundance of Pedobacter, Anaeroplasma, Paludibacter, Ruminococcus, and unclassified Lachnospiraceae was positively correlated with the CH 4 production, with no effects on volatile fatty acids. This study suggests that medicinal herbs may be used to mitigate the CH 4 emission from ruminants.

Methane Seepage on Mars: Where to Look and Why.

PubMed

Oehler, Dorothy Z; Etiope, Giuseppe

2017-12-01

Methane on Mars is a topic of special interest because of its potential association with microbial life. The variable detections of methane by the Curiosity rover, orbiters, and terrestrial telescopes, coupled with methane's short lifetime in the martian atmosphere, may imply an active gas source in the planet's subsurface, with migration and surface emission processes similar to those known on Earth as "gas seepage." Here, we review the variety of subsurface processes that could result in methane seepage on Mars. Such methane could originate from abiotic chemical reactions, thermogenic alteration of abiotic or biotic organic matter, and ancient or extant microbial metabolism. These processes can occur over a wide range of temperatures, in both sedimentary and igneous rocks, and together they enhance the possibility that significant amounts of methane could have formed on early Mars. Methane seepage to the surface would occur preferentially along faults and fractures, through focused macro-seeps and/or diffuse microseepage exhalations. Our work highlights the types of features on Mars that could be associated with methane release, including mud-volcano-like mounds in Acidalia or Utopia; proposed ancient springs in Gusev Crater, Arabia Terra, and Valles Marineris; and rims of large impact craters. These could have been locations of past macro-seeps and may still emit methane today. Microseepage could occur through faults along the dichotomy or fractures such as those at Nili Fossae, Cerberus Fossae, the Argyre impact, and those produced in serpentinized rocks. Martian microseepage would be extremely difficult to detect remotely yet could constitute a significant gas source. We emphasize that the most definitive detection of methane seepage from different release candidates would be best provided by measurements performed in the ground or at the ground-atmosphere interface by landers or rovers and that the technology for such detection is currently available. Key Words: Mars-Methane-Seepage-Clathrate-Fischer-Tropsch-Serpentinization. Astrobiology 17, 1233-1264.

Why Methane Increasing in the Atmosphere is Pushing us Towards New Analytical Approaches for Stable Isotope Ratios

NASA Astrophysics Data System (ADS)

White, J. W. C.; Michel, S. E.; Vaughn, B. H.; Miller, J. B.; Masarie, K. A.; Dlugokencky, E. J.; Sherwood, O.; Tans, P. P.

2015-12-01

Methane is increasing again in the atmosphere after nearly a decade of stable concentrations. As methane has risen by 2.5 times since the beginning of the industrial era, such a rise in concentrations is not surprising. Carbon isotopes, however, make it clear that the recent rise is not simply a resumption of the dramatic rise in the 1900s, but that other causes are at play, and that multiple fluxes may be interacting to yield the observed rise. At the same time, cautious attention is focused on the Arctic, where vast stores of carbon are poised for release as frozen soils melt, and some of that carbon will be released as methane. These realities make it imperative that we improve our monitoring of methane and methane isotopes in the atmosphere. This talk will address the issues that we face in meeting this challenge in the NOAA Global Greenhouse Gas Reference Network, including targets for precision and accuracy needed to calculate regional and global fluxes, technological advances in analytical equipment, maintaining standards, ensuring adequate monitoring sites and meeting all of these needs in an era of funding cuts and uncertainty for environmental monitoring.

Assessing Methane in Shallow Groundwater in Unconventional Oil and Gas Play Areas, Eastern Kentucky.

PubMed

Zhu, Junfeng; Parris, Thomas M; Taylor, Charles J; Webb, Steven E; Davidson, Bart; Smath, Richard; Richardson, Stephen D; Molofsky, Lisa J; Kromann, Jenna S; Smith, Ann P

2018-05-01

The expanding use of horizontal drilling and hydraulic fracturing technology to produce oil and gas from tight rock formations has increased public concern about potential impacts on the environment, especially on shallow drinking water aquifers. In eastern Kentucky, horizontal drilling and hydraulic fracturing have been used to develop the Berea Sandstone and the Rogersville Shale. To assess baseline groundwater chemistry and evaluate methane detected in groundwater overlying the Berea and Rogersville plays, we sampled 51 water wells and analyzed the samples for concentrations of major cations and anions, metals, dissolved methane, and other light hydrocarbon gases. In addition, the stable carbon and hydrogen isotopic composition of methane (δ 13 C-CH 4 and δ 2 H-CH 4 ) was analyzed for samples with methane concentration exceeding 1 mg/L. Our study indicates that methane is a relatively common constituent in shallow groundwater in eastern Kentucky, where methane was detected in 78% of the sampled wells (40 of 51 wells) with 51% of wells (26 of 51 wells) exhibiting methane concentrations above 1 mg/L. The δ 13 C-CH 4 and δ 2 H-CH 4 ranged from -84.0‰ to -58.3‰ and from -246.5‰ to -146.0‰, respectively. Isotopic analysis indicated that dissolved methane was primarily microbial in origin formed through CO 2 reduction pathway. Results from this study provide a first assessment of methane in the shallow aquifers in the Berea and Rogersville play areas and can be used as a reference to evaluate potential impacts of future horizontal drilling and hydraulic fracturing activities on groundwater quality in the region. © 2017, National Ground Water Association.

Utilization of coal mine methane for methanol and SCP production. Topical report, May 5, 1995--March 4, 1996

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1998-12-31

The feasibility of utilizing a biological process to reduce methane emissions from coal mines and to produce valuable single cell protein (SCP) and/or methanol as a product has been demonstrated. The quantities of coal mine methane from vent gas, gob wells, premining wells and abandoned mines have been determined in order to define the potential for utilizing mine gases as a resource. It is estimated that 300 MMCFD of methane is produced in the United States at a typical concentration of 0.2-0.6 percent in ventilation air. Of this total, almost 20 percent is produced from the four Jim Walter Resourcesmore » (JWR) mines, which are located in very gassy coal seams. Worldwide vent gas production is estimated at 1 BCFD. Gob gas methane production in the U.S. is estimated to be 38 MMCFD. Very little gob gas is produced outside the U.S. In addition, it is estimated that abandoned mines may generate as much as 90 MMCFD of methane. In order to make a significant impact on coal mine methane emissions, technology which is able to utilize dilute vent gases as a resource must be developed. Purification of the methane from the vent gases would be very expensive and impractical. Therefore, the process application must be able to use a dilute methane stream. Biological conversion of this dilute methane (as well as the more concentrated gob gases) to produce single cell protein (SCP) and/or methanol has been demonstrated in the Bioengineering Resources, Inc. (BRI) laboratories. SCP is used as an animal feed supplement, which commands a high price, about $0.11 per pound.« less

Development of feeding systems and strategies of supplementation to enhance rumen fermentation and ruminant production in the tropics

PubMed Central

2013-01-01

The availability of local feed resources in various seasons can contribute as essential sources of carbohydrate and protein which significantly impact rumen fermentation and the subsequent productivity of the ruminant. Recent developments, based on enriching protein in cassava chips, have yielded yeast fermented cassava chip protein (YEFECAP) providing up to 47.5% crude protein (CP), which can be used to replace soybean meal. The use of fodder trees has been developed through the process of pelleting; Leucaena leucocephala leaf pellets (LLP), mulberry leaf pellets (MUP) and mangosteen peel and/or garlic pellets, can be used as good sources of protein to supplement ruminant feeding. Apart from producing volatile fatty acids and microbial proteins, greenhouse gases such as methane are also produced in the rumen. Several methods have been used to reduce rumen methane. However, among many approaches, nutritional manipulation using feed formulation and feeding management, especially the use of plant extracts or plants containing secondary compounds (condensed tannins and saponins) and plant oils, has been reported. This approach could help todecrease rumen protozoa and methanogens and thus mitigate the production of methane. At present, more research concerning this burning issue - the role of livestock in global warming - warrants undertaking further research with regard to economic viability and practical feasibility. PMID:23981662

Kinetic study on anaerobic oxidation of methane coupled to denitrification.

PubMed

Yu, Hou; Kashima, Hiroyuki; Regan, John M; Hussain, Abid; Elbeshbishy, Elsayed; Lee, Hyung-Sool

2017-09-01

Monod kinetic parameters provide information required for kinetic analysis of anaerobic oxidation of methane coupled to denitrification (AOM-D). This information is critical for engineering AOM-D processes in wastewater treatment facilities. We first experimentally determined Monod kinetic parameters for an AOM-D enriched culture and obtained the following values: maximum specific growth rate (μ max ) 0.121/d, maximum substrate-utilization rate (q max ) 28.8mmol CH 4 /g cells-d, half maximum-rate substrate concentration (K s ) 83μΜ CH 4 , growth yield (Y) 4.76gcells/mol CH 4 , decay coefficient (b) 0.031/d, and threshold substrate concentration (S min ) 28.8μM CH 4 . Clone library analysis of 16S rRNA and mcrA gene fragments suggested that AOM-D reactions might have occurred via the syntrophic interaction between denitrifying bacteria (e.g., Ignavibacterium, Acidovorax, and Pseudomonas spp.) and hydrogenotrophic methanogens (Methanobacterium spp.), supporting reverse methanogenesis-dependent AOM-D in our culture. High μ max and q max , and low K s for the AOM-D enrichment imply that AOM-D could play a significant role in mitigating atmospheric methane efflux. In addition, these high kinetic features suggest that engineered AOM-D systems may provide a sustainable alternative to nitrogen removal in wastewater treatment. Copyright © 2017 Elsevier Inc. All rights reserved.

Aerospace Fuels From Nonpetroleum Raw Materials

NASA Technical Reports Server (NTRS)

Palaszewski, Bryan A.; Hepp, Aloysius F.; Kulis, Michael J.; Jaworske, Donald A.

2013-01-01

Recycling human metabolic and plastic wastes minimizes cost and increases efficiency by reducing the need to transport consumables and return trash, respectively, from orbit to support a space station crew. If the much larger costs of transporting consumables to the Moon and beyond are taken into account, developing waste recycling technologies becomes imperative and possibly mission enabling. Reduction of terrestrial waste streams while producing energy and/or valuable raw materials is an opportunity being realized by a new generation of visionary entrepreneurs; several relevant technologies are briefly compared, contrasted and assessed for space applications. A two-step approach to nonpetroleum raw materials utilization is presented; the first step involves production of supply or producer gas. This is akin to synthesis gas containing carbon oxides, hydrogen, and simple hydrocarbons. The second step involves production of fuel via the Sabatier process, a methanation reaction, or another gas-to-liquid technology, typically Fischer-Tropsch processing. Optimization to enhance the fraction of product stream relevant to transportation fuels via catalytic (process) development at NASA Glenn Research Center is described. Energy utilization is a concern for production of fuels whether for operation on the lunar or Martian surface, or beyond. The term green relates to not only mitigating excess carbon release but also to the efficiency of energy usage. For space, energy usage can be an essential concern. Another issue of great concern is minimizing impurities in the product stream(s), especially those that are potential health risks and/or could degrade operations through catalyst poisoning or equipment damage; technologies being developed to remove heteroatom impurities are discussed. Alternative technologies to utilize waste fluids, such as a propulsion option called the resistojet, are discussed. The resistojet is an electric propulsion technology with a powered thruster to vaporize and heat a propellant to high temperature, hot gases are subsequently passed through a converging-diverging nozzle expanding gases to supersonic velocities. A resistojet can accommodate many different fluids, including various reaction chamber (by-)products.

Aerospace Fuels from Nonpetroleum Raw Materials

NASA Technical Reports Server (NTRS)

Palaszewski, B. A.; Hepp, A. F.; Kulis, M. J.; Jaworske, D. A.

2013-01-01

Recycling human metabolic and plastic wastes minimizes cost and increases efficiency by reducing the need to transport consumables and return trash, respectively, from orbit to support a space station crew. If the much larger costs of transporting consumables to the Moon and beyond are taken into account, developing waste recycling technologies becomes imperative and possibly mission enabling. Reduction of terrestrial waste streams while producing energy and/or valuable raw materials is an opportunity being realized by a new generation of visionary entrepreneurs; several relevant technologies are briefly compared, contrasted and assessed for space applications. A two-step approach to nonpetroleum raw materials utilization is presented; the first step involves production of supply or producer gas. This is akin to synthesis gas containing carbon oxides, hydrogen, and simple hydrocarbons. The second step involves production of fuel via the Sabatier process, a methanation reaction, or another gas-to-liquid technology, typically Fischer- Tropsch processing. Optimization to enhance the fraction of product stream relevant to transportation fuels via catalytic (process) development at NASA GRC is described. Energy utilization is a concern for production of fuels whether for operation on the lunar or Martian surface, or beyond. The term "green" relates to not only mitigating excess carbon release but also to the efficiency of energy usage. For space, energy usage can be an essential concern. Other issues of great concern include minimizing impurities in the product stream(s), especially those that are potential health risks and/or could de-grade operations through catalyst poisoning or equipment damage; technologies being developed to remove heteroatom impurities are discussed. Alternative technologies to utilize waste fluids, such as a propulsion option called the resistojet, are discussed. The resistojet is an electric propulsion technology with a powered thruster to vaporize and heat a propellant to high temperature, hot gases are subsequently passed through a converging-diverging nozzle expanding gases to supersonic velocities. A resistojet can accommodate many different fluids, including various reaction chamber (by-)products.

Coalbed methane: Clean energy for the world

USGS Publications Warehouse

Ahmed, A.-J.; Johnston, S.; Boyer, C.; Lambert, S.W.; Bustos, O.A.; Pashin, J.C.; Wray, A.

2009-01-01

Coalbed methane (CBM) has the potential to emerge as a significant clean energy resource. It also has the potential to replace other diminishing hydrocarbon reserves. The latest developments in technologies and methodologies are playing a key role in harnessing this unconventional resource. Some of these developments include adaptations of existing technologies used in conventional oil and gas generations, while others include new applications designed specifically to address coal's unique properties. Completion techniques have been developed that cause less damage to the production mechanisms of coal seams, such as those occurring during cementing operations. Stimulation fluids have also been engineered specifically to enhance CBM production. Deep coal deposits that remain inaccessible by conventional mining operations offer CBM development opportunities.

Air pollution and climate-forcing impacts of a global hydrogen economy.

PubMed

Schultz, Martin G; Diehl, Thomas; Brasseur, Guy P; Zittel, Werner

2003-10-24

If today's surface traffic fleet were powered entirely by hydrogen fuel cell technology, anthropogenic emissions of the ozone precursors nitrogen oxide (NOx) and carbon monoxide could be reduced by up to 50%, leading to significant improvements in air quality throughout the Northern Hemisphere. Model simulations of such a scenario predict a decrease in global OH and an increased lifetime of methane, caused primarily by the reduction of the NOx emissions. The sign of the change in climate forcing caused by carbon dioxide and methane depends on the technology used to generate the molecular hydrogen. A possible rise in atmospheric hydrogen concentrations is unlikely to cause significant perturbations of the climate system.

Summary of performance data for technologies to control gaseous, odor, and particulate emissions from livestock operations: Air management practices assessment tool (AMPAT)

PubMed Central

Maurer, Devin L.; Koziel, Jacek A.; Harmon, Jay D.; Hoff, Steven J.; Rieck-Hinz, Angela M.; Andersen, Daniel S.

2016-01-01

The livestock and poultry production industry, regulatory agencies, and researchers lack a current, science-based guide and data base for evaluation of air quality mitigation technologies. Data collected from science-based review of mitigation technologies using practical, stakeholders-oriented evaluation criteria to identify knowledge gaps/needs and focuses for future research efforts on technologies and areas with the greatest impact potential is presented in the Literature Database tab on the air management practices tool (AMPAT). The AMPAT is web-based (available at www.agronext.iastate.edu/ampat) and provides an objective overview of mitigation practices best suited to address odor, gaseous, and particulate matter (PM) emissions at livestock operations. The data was compiled into Excel spreadsheets from a literature review of 265 papers was performed to (1) evaluate mitigation technologies performance for emissions of odor, volatile organic compounds (VOCs), ammonia (NH3), hydrogen sulfide (H2S), particulate matter (PM), and greenhouse gases (GHGs) and to (2) inform future research needs. PMID:27158660

Is Teacher Professional Development an Effective Way to Mitigate Teachers' Gender Differences in Technology? Result from a Statewide Teacher Professional Development Program

ERIC Educational Resources Information Center

Li, Yi

2016-01-01

This study analyzed data from a statewide professional development (PD) program to investigate whether gender difference towards technology usage was mitigated after participation in the program. Teachers responded to pre- and post-questionnaires regarding their perceptions and use of technology before and after participating in PD courses.…

Near Earth Object (NEO) Mitigation Options Using Exploration Technologies

NASA Technical Reports Server (NTRS)

Arnold William; Baysinger, Mike; Crane, Tracie; Capizzo, Pete; Sutherlin, Steven; Dankanich, John; Woodcock, Gordon; Edlin, George; Rushing, Johnny; Fabisinski, Leo;

Hydrogen Purification and Recycling for an Integrated Oxygen Recovery System Architecture

NASA Technical Reports Server (NTRS)

Abney, Morgan B.; Greenwood, Zachary; Wall, Terry; Miller, Lee; Wheeler, Ray

2016-01-01

The United States Atmosphere Revitalization life support system on the International Space Station (ISS) performs several services for the crew including oxygen generation, trace contaminant control, carbon dioxide (CO2) removal, and oxygen recovery. Oxygen recovery is performed using a Sabatier reactor developed by Hamilton Sundstrand, wherein CO2 is reduced with hydrogen in a catalytic reactor to produce methane and water. The water product is purified in the Water Purification Assembly and recycled to the Oxygen Generation Assembly (OGA) to provide O2 to the crew. This architecture results in a theoretical maximum oxygen recovery from CO2 of approximately 54% due to the loss of reactant hydrogen in Sabatier-produced methane that is currently vented outside of ISS. Plasma Methane Pyrolysis technology (PPA), developed by Umpqua Research Company, provides the capability to further close the Atmosphere Revitalization oxygen loop by recovering hydrogen from Sabatier-produced methane. A key aspect of this technology approach is to purify the hydrogen from the PPA product stream which includes acetylene, unreacted methane and byproduct water and carbon monoxide. In 2015, four sub-scale hydrogen separation systems were delivered to NASA for evaluation. These included two electrolysis single-cell hydrogen purification cell stacks developed by Sustainable Innovations, LLC, a sorbent-based hydrogen purification unit using microwave power for sorbent regeneration developed by Umpqua Research Company, and a LaNi4.6Sn0.4 metal hydride produced by Hydrogen Consultants, Inc. Here we report the results of these evaluations, discuss potential architecture options, and propose future work.

Low-thrust chemical propulsion system pump technology

NASA Technical Reports Server (NTRS)

Meadville, J. W.

1980-01-01

A study was conducted within the thrust range 450 to 9000 N (100 to 2000 pounds). Performance analyses were made on centrifugal, pitot, Barske, drag, Tesla, gear, piston, lobe, and vane pumps with liquid hydrogen, liquid methane, and liquid oxygen as propellants. Gaseous methane and hydrogen driven axial impulse turbines, vane expanders, piston expanders, and electric motors were studied as drivers. Data are presented on performance, sizes, weights, and estimated service lives and costs.

Methane and Methanol Oxidation in Supercritical Water: Chemical Kinetics and Hydrothermal Flame Studies

DTIC Science & Technology

1996-01-01

water at 270 bar and at temperatures from 390 to 442 ’C. The initial methane concentration was nominally 0.15 gmol/L, a level representa- tive of...compounds appropriate for treatment with SCWO technology (Modell, 1989). Since then, the need to understand reaction chemistry has motivated extensive...understand the physics and chemistry controlling oxidation in supercritical water; to contribute to combustion science by performing fundamental studies in a

Design and operation of an anaerobic digester for waste management and fuel generation during long term lunar mission

NASA Astrophysics Data System (ADS)

Dhoble, Abhishek S.; Pullammanappallil, Pratap C.

2014-10-01

Waste treatment and management for manned long term exploratory missions to moon will be a challenge due to longer mission duration. The present study investigated appropriate digester technologies that could be used on the base. The effect of stirring, operation temperature, organic loading rate and reactor design on the methane production rate and methane yield was studied. For the same duration of digestion, the unmixed digester produced 20-50% more methane than mixed system. Two-stage design which separated the soluble components from the solids and treated them separately had more rapid kinetics than one stage system, producing the target methane potential in one-half the retention time than the one stage system. The two stage system degraded 6% more solids than the single stage system. The two stage design formed the basis of a prototype digester sized for a four-person crew during one year exploratory lunar mission.

Development of an advanced anaerobic digester design and a kinetic model for biogasification of water hyacinth/sludge blends

DOE Office of Scientific and Technical Information (OSTI.GOV)

Srivastava, V.; Fannin, K.F.; Biljetina, R.

1986-07-01

The Institute of Gas Technology (IGT) conducted a comprehensive laboratory-scale research program to develop and optimize the anaerobic digestion process for producing methane from water hyacinth and sludge blends. This study focused on digester design and operating techniques, which gave improved methane yields and production rates over those observed using conventional digesters. The final digester concept and the operating experience was utilized to design and operate a large-scale experimentla test unit (ETU) at Walt Disney World, Florida. This paper describes the novel digester design, operating techniques, and the results obtained in the laboratory. The paper also discusses a kinetic modelmore » which predicts methane yield, methane production rate, and digester effluent solids as a function of retention time. This model was successfully utilized to predict the performance of the ETU. 15 refs., 6 figs., 6 tabs.« less

Laser system for natural gas detection. Phase 1: Laboratory feasibility studies

NASA Technical Reports Server (NTRS)

Grant, W. B.; Hinkley, E. D., Jr.

1982-01-01

This project demonstrated the feasibility of using laser remote sensing technology as a tool for leak survey work in natural gas distribution systems. A laboratory device was assembled using a pair of helium neon (HeNe) lasers to measure methane. One HeNe laser emits radiation at a wavelength of 3.3922 micrometers, which corresponds to a strong absorption feature of methane, while the other emits radiation at a wavelength of 3.3911 micrometers, which corresponds to a weak absorption by methane. As a particular area is scanned for leaks, the laser is pointed at convenient topographic targets within its operating range, about 25 m. A portion of the backscattered radiation is collected by a receiver and focused onto an indium antimonide (InSb) photodetector, cooled to 77K. Methane concentrations were determined from the differential absorption at the two wavelengths for the backscattered radiation.

Methane for Power Generation in Muaro Jambi: A Green Prosperity Model Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moriarty, K.; Elchinger, M.; Hill, G.

2014-07-01

NREL conducted eight model projects for Millennium Challenge Corporation's (MCC) Compact with Indonesia. Green Prosperity, the largest project of the Compact, seeks to address critical constraints to economic growth while supporting the Government of Indonesia's commitment to a more sustainable, less carbon-intensive future. This study evaluates electricity generation from the organic content of wastewater at a palm oil mill in Muaro Jambi, Sumatra. Palm mills use vast amounts of water in the production process resulting in problematic waste water called palm oil mill effluent (POME). The POME releases methane to the atmosphere in open ponds which could be covered tomore » capture the methane to produce renewable electricity for rural villages. The study uses average Indonesia data to determine the economic viability of methane capture at a palm oil mill and also evaluates technology as well as social and environmental impacts of the project.« less

Adsorbed Natural Gas Storage in Optimized High Surface Area Microporous Carbon

NASA Astrophysics Data System (ADS)

Romanos, Jimmy; Rash, Tyler; Nordwald, Erik; Shocklee, Joshua Shawn; Wexler, Carlos; Pfeifer, Peter

2011-03-01

Adsorbed natural gas (ANG) is an attractive alternative technology to compressed natural gas (CNG) or liquefied natural gas (LNG) for the efficient storage of natural gas, in particular for vehicular applications. In adsorbants engineered to have pores of a few molecular diameters, a strong van der Walls force allows reversible physisorption of methane at low pressures and room temperature. Activated carbons were optimized for storage by varying KOH:C ratio and activation temperature. We also consider the effect of mechanical compression of powders to further enhance the volumetric storage capacity. We will present standard porous material characterization (BET surface area and pore-size distribution from subcritical N2 adsorption) and methane isotherms up to 250 bar at 293K. At sufficiently high pressure, specific surface area, methane binding energy and film density can be extracted from supercritical methane adsorption isotherms. Research supported by the California Energy Commission (500-08-022).

Methane Explosion Mitigation in Coal Mines by Water Mist

NASA Astrophysics Data System (ADS)

Chikhradze, Nikoloz; Mataradze, Edgar; Chikhradze, Mikheil; Krauthammer, Ted; Mansurov, Zulkhair; Alyiev, Erhan

2017-12-01

Statistics shows that the majority of accidents with fatal outcome are caused by methane and/or coal dust explosion. This leads to assume that contemporary counter-explosion systems of various designs cannot be considered effective. Considering the growing threat of methane explosion in the coming years along with the development of deeper levels, the improvement of a system for protecting people in underground opening appears urgent. This paper focuses on technical solutions to be used in designing a protective system for minimizing the consequences of methane explosions in coalmines. The new protective system consists of three main modules: i) a high-speed shock wave suppression section; ii) a suppression section with a long-term action and iii) a system activating device. The shock wave suppressor contains a 200 litre volume water tank with a built-in gas generator and nozzles. It is activated after 12ms from the blast moment, the duration of discharge is 40 s. The suppression section with a long-term action contains a 2000 litre volume water tank, a high-pressure pump, a hydraulic accumulator, solenoid valves, and a system of pipes with built-in nozzles. It is activated after 4 s from the blast moment, the duration of discharge is 8 min. The activation device includes a detection block containing sensors, an emergency signal generation module, a signal transmission module, a signal receiving module and a power supply module. The system operates in a waiting mode and activates immediately upon the receipt of the start signal generated by the detector. The paper also addresses the preliminary results of the system prototype testing in the tunnel.

Production of Methane and Water from Crew Plastic Waste

NASA Technical Reports Server (NTRS)

Captain, Janine; Santiago, Eddie; Parrish, Clyde; Strayer, Richard F.; Garland, Jay L.

2008-01-01

Recycling is a technology that will be key to creating a self sustaining lunar outpost. The plastics used for food packaging provide a source of material that could be recycled to produce water and methane. The recycling of these plastics will require some additional resources that will affect the initial estimate of starting materials that will have to be transported from earth, mainly oxygen, energy and mass. These requirements will vary depending on the recycling conditions. The degredation products of these plastics will vary under different atmospheric conditions. An estimate of the the production rate of methane and water using typical ISRU processes along with the plastic recycling will be presented.

Anaerobic digestion of water hyacinth and sludge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biljetina, R.; Srivastava, V.J.; Chynoweth, D.P.

1986-01-01

The Institute of Gas Technology (IGT) has been operating an experimental test unit (ETU) at the Walt Disney World (WDW) wastewater treatment plant to demonstrate the conversion of water hyacinth and sludge to methane in a solids concentrating (SOLCON) digester. Results from 2 years to operation have confirmed earlier laboratory observations that this digester achieves higher methane yields and solids conversion than those observed in continuous stirred tank reactors. Methane yields as high as 0.49 m/sup 3/ kg/sup -1/ (7.9 SCF/lb) volatile solids added have been obtained during steady-state operation on a blend of water hyacinth and sludge. 9 refs.,more » 5 figs., 5 tabs.« less

Tuneable diode laser gas analyser for methane measurements on a large scale solid oxide fuel cell

NASA Astrophysics Data System (ADS)

Lengden, Michael; Cunningham, Robert; Johnstone, Walter

2011-10-01

A new in-line, real time gas analyser is described that uses tuneable diode laser spectroscopy (TDLS) for the measurement of methane in solid oxide fuel cells. The sensor has been tested on an operating solid oxide fuel cell (SOFC) in order to prove the fast response and accuracy of the technology as compared to a gas chromatograph. The advantages of using a TDLS system for process control in a large-scale, distributed power SOFC unit are described. In future work, the addition of new laser sources and wavelength modulation will allow the simultaneous measurement of methane, water vapour, carbon-dioxide and carbon-monoxide concentrations.

Atmospheric Methane at Cape Meares\\, Oregon\\, U.S.A.: A High-Resolution Data Base for the Period 1979-1992

DOE Data Explorer

Khalil, M. A.K. [Oregon Graduate Institute of Science and Technology; Rasmussen, R. A. [Oregon Graduate Institute of Science and Technology

1994-01-01

This data base presents continuous automated atmospheric methane (CH4) measurements taken at the atmospheric monitoring facility in Cape Meares, Oregon, by the Oregon Graduate Institute of Science and Technology. The Cape Meares data represent some 119,000 individual atmospheric methane measurements carried out during 1979-1992. Analysis of ambient air (collected 12 to 72 times daily) was carried out by means of an automated sampling and measurement system, using the method of gas chromatography and flame ionization detection. Despite the long course of the record and the large number of individual measurements, these data may all be linked to a single absolute calibration standard.

Climate change and eHealth: a promising strategy for health sector mitigation and adaptation

PubMed Central

Holmner, Åsa; Rocklöv, Joacim; Ng, Nawi; Nilsson, Maria

2012-01-01

Climate change is one of today's most pressing global issues. Policies to guide mitigation and adaptation are needed to avoid the devastating impacts of climate change. The health sector is a significant contributor to greenhouse gas emissions in developed countries, and its climate impact in low-income countries is growing steadily. This paper reviews and discusses the literature regarding health sector mitigation potential, known and hypothetical co-benefits, and the potential of health information technology, such as eHealth, in climate change mitigation and adaptation. The promising role of eHealth as an adaptation strategy to reduce societal vulnerability to climate change, and the link's between mitigation and adaptation, are also discussed. The topic of environmental eHealth has gained little attention to date, despite its potential to contribute to more sustainable and green health care. A growing number of local and global initiatives on ‘green information and communication technology (ICT)’ are now mentioning eHealth as a promising technology with the potential to reduce emission rates from ICT use. However, the embracing of eHealth is slow because of limitations in technological infrastructure, capacity and political will. Further research on potential emissions reductions and co-benefits with green ICT, in terms of health outcomes and economic effectiveness, would be valuable to guide development and implementation of eHealth in health sector mitigation and adaptation policies. PMID:22679398

Climate change and eHealth: a promising strategy for health sector mitigation and adaptation.

PubMed

Holmner, Asa; Rocklöv, Joacim; Ng, Nawi; Nilsson, Maria

2012-01-01

Climate change is one of today's most pressing global issues. Policies to guide mitigation and adaptation are needed to avoid the devastating impacts of climate change. The health sector is a significant contributor to greenhouse gas emissions in developed countries, and its climate impact in low-income countries is growing steadily. This paper reviews and discusses the literature regarding health sector mitigation potential, known and hypothetical co-benefits, and the potential of health information technology, such as eHealth, in climate change mitigation and adaptation. The promising role of eHealth as an adaptation strategy to reduce societal vulnerability to climate change, and the link's between mitigation and adaptation, are also discussed. The topic of environmental eHealth has gained little attention to date, despite its potential to contribute to more sustainable and green health care. A growing number of local and global initiatives on 'green information and communication technology (ICT)' are now mentioning eHealth as a promising technology with the potential to reduce emission rates from ICT use. However, the embracing of eHealth is slow because of limitations in technological infrastructure, capacity and political will. Further research on potential emissions reductions and co-benefits with green ICT, in terms of health outcomes and economic effectiveness, would be valuable to guide development and implementation of eHealth in health sector mitigation and adaptation policies.

Testing of a Liquid Oxygen/Liquid Methane Reaction Control Thruster in a New Altitude Rocket Engine Test Facility

NASA Technical Reports Server (NTRS)

Meyer, Michael L.; Arrington, Lynn A.; Kleinhenz, Julie E.; Marshall, William M.

2012-01-01

A relocated rocket engine test facility, the Altitude Combustion Stand (ACS), was activated in 2009 at the NASA Glenn Research Center. This facility has the capability to test with a variety of propellants and up to a thrust level of 2000 lbf (8.9 kN) with precise measurement of propellant conditions, propellant flow rates, thrust and altitude conditions. These measurements enable accurate determination of a thruster and/or nozzle s altitude performance for both technology development and flight qualification purposes. In addition the facility was designed to enable efficient test operations to control costs for technology and advanced development projects. A liquid oxygen-liquid methane technology development test program was conducted in the ACS from the fall of 2009 to the fall of 2010. Three test phases were conducted investigating different operational modes and in addition, the project required the complexity of controlling propellant inlet temperatures over an extremely wide range. Despite the challenges of a unique propellant (liquid methane) and wide operating conditions, the facility performed well and delivered up to 24 hot fire tests in a single test day. The resulting data validated the feasibility of utilizing this propellant combination for future deep space applications.

Optimization of municipal sludge and grease co-digestion using disintegration technologies.

PubMed

Bouchy, L; Pérez, A; Camacho, P; Rubio, P; Silvestre, G; Fernández, B; Cano, R; Polanco, M; Díaz, N

2012-01-01

Many drivers tend to foster the development of renewable energy production in wastewater treatment plants as many expectations rely upon energy recovery from sewage sludge, for example through biogas use. This paper is focused on the assessment of grease waste (GW) as an adequate substrate for co-digestion with municipal sludge, as it has a methane potential of 479-710 LCH(4)/kg VS, as well as the evaluation of disintegration technologies as a method to optimize the co-digestion process. With this objective three different pre-treatments have been selected for evaluation: thermal hydrolysis, ultrasound and enzymatic treatment. Results have shown that co-digestion processes without pre-treatment had a maximum increment of 128% of the volumetric methane productivity when GW addition was 23% inlet (at 20 days of HRT and with an OLR of 3.0 kg COD/m(3)d), compared with conventional digestion of sewage sludge alone. Concerning the application of the selected disintegration technologies, all pre-treatments showed improvements in terms of methane yield (51.8, 89.5 and 57.6% more for thermal hydrolysis, ultrasound and enzymatic treatment, respectively, compared with non-pretreated wastes), thermal hydrolysis of GW and secondary sludge being the best configuration as it improved the solubilization of the organic matter and the hydrodynamic characteristics of digestates.

Study on Characteristics of Co-firing Ammonia/Methane Fuels under Oxygen Enriched Combustion Conditions

NASA Astrophysics Data System (ADS)

Xiao, Hua; Wang, Zhaolin; Valera-Medina, Agustin; Bowen, Philip J.

2018-06-01

Having a background of utilising ammonia as an alternative fuel for power generation, exploring the feasibility of co-firing ammonia with methane is proposed to use ammonia to substitute conventional natural gas. However, improvement of the combustion of such fuels can be achieved using conditions that enable an increase of oxygenation, thus fomenting the combustion process of a slower reactive molecule as ammonia. Therefore, the present study looks at oxygen enriched combustion technologies, a proposed concept to improve the performance of ammonia/methane combustion. To investigate the characteristics of ammonia/methane combustion under oxygen enriched conditions, adiabatic burning velocity and burner stabilized laminar flame emissions were studied. Simulation results show that the oxygen enriched method can help to significantly enhance the propagation of ammonia/methane combustion without changing the emission level, which would be quite promising for the design of systems using this fuel for practical applications. Furthermore, to produce low computational-cost flame chemistry for detailed numerical analyses for future combustion studies, three reduced combustion mechanisms of the well-known Konnov's mechanism were compared in ammonia/methane flame simulations under practical gas turbine combustor conditions. Results show that the reduced reaction mechanisms can provide good results for further analyses of oxygen enriched combustion of ammonia/methane. The results obtained in this study also allow gas turbine designers and modellers to choose the most suitable mechanism for further combustion studies and development.

Stimulation Of The Methane Production With The Use Of Changing Of The Rock Massif Physical Conditions

NASA Astrophysics Data System (ADS)

Baev, Mikhail; Khyamyalyaynen, Veniamin; Shevtsov, Aleksandr

2017-11-01

The commercial coalbed methane production success is majorly defined by the effectiveness of the use of special gas inflow stimulation methods. The necessity of using of such methods issubject to the aspects of searching and displacement of methane within the coal compound. Theanalysis of the ways of methane production stimulation from virgin coal formations is given. The description of the process of hydraulic fracturing (fracturing) as the most common stimulation method during the commercial coalbed methane production as well as its major advantages are presented. The present work provides data about the initiated laboratory research of sands collected from Kemerovo region deposits for the purpose of finding of the most prospective samples by means of anchoring of fractures. The prospectivity and ability to implement the hydraulic fracturing with the use of locally available sands acting as proppants are shown. The influence of the strain-stress state of the rock massif on the alteration of permeability and the necessity of its extension study with respect to different technological features of hydraulic fracturing is shown

Kinetic modelling of methane production during bio-electrolysis from anaerobic co-digestion of sewage sludge and food waste.

PubMed

Prajapati, Kalp Bhusan; Singh, Rajesh

2018-05-10

In present study batch tests were performed to investigate the enhancement in methane production under bio-electrolysis anaerobic co-digestion of sewage sludge and food waste. The bio-electrolysis reactor system (B-EL) yield more methane 148.5 ml/g COD in comparison to reactor system without bio-electrolysis (B-CONT) 125.1 ml/g COD. Whereas bio-electrolysis reactor system (C-EL) Iron Scraps amended yield lesser methane (51.2 ml/g COD) in comparison to control bio-electrolysis reactor system without Iron scraps (C-CONT - 114.4 ml/g COD). Richard and Exponential model were best fitted for cumulative methane production and biogas production rates respectively as revealed modelling study. The best model fit for the different reactors was compared by Akaike's Information Criterion (AIC) and Bayesian Information Criterion (BIC). The bioelectrolysis process seems to be an emerging technology with lesser the loss in cellulase specific activity with increasing temperature from 50 to 80 °C. Copyright © 2018 Elsevier Ltd. All rights reserved.

Identification, Attribution, and Quantification of Highly Heterogeneous Methane Sources Using a Mobile Stable Isotope Analyzer

NASA Astrophysics Data System (ADS)

Crosson, E.; Rella, C.; Cunningham, K.

2012-04-01

Despite methane's importance as a potent greenhouse gas second only to carbon dioxide in the magnitude of its contribution to global warming, natural contributions to the overall methane budget are only poorly understood. A big contributor to this gap in knowledge is the highly spatially and temporally heterogeneous nature of most natural (and for that matter anthropogenic) methane sources. This high degree of heterogeneity, where the methane emission rates can vary over many orders of magnitude on a spatial scale of meters or even centimeters, and over a temporal scale of minutes or even seconds, means that traditional methods of emissions flux estimation, such as flux chambers or eddy-covariance, are difficult or impossible to apply. In this paper we present new measurement methods that are capable of detecting, attributing, and quantifying emissions from highly heterogeneous sources. These methods take full advantage of the new class of methane concentration and stable isotope analyzers that are capable of laboratory-quality analysis from a mobile field platform in real time. In this paper we present field measurements demonstrating the real-time detection of methane 'hot spots,' attribution of the methane to a source process via real-time stable isotope analysis, and quantification of the emissions flux using mobile concentration measurements of the horizontal and vertical atmospheric dispersion, combined with atmospheric transport calculations. Although these techniques are applicable to both anthropogenic and natural methane sources, in this initial work we focus primarily on landfills and fugitive emissions from natural gas distribution, as these sources are better characterized, and because they provide a more reliable and stable source of methane for quantifying the measurement uncertainty inherent in the different methods. Implications of these new technologies and techniques are explored for the quantification of natural methane sources in a variety of environments, including wetlands, peatlands, and the arctic.

Methane Seepage on Mars: Where to Look and Why

PubMed Central

Etiope, Giuseppe

2017-01-01

Abstract Methane on Mars is a topic of special interest because of its potential association with microbial life. The variable detections of methane by the Curiosity rover, orbiters, and terrestrial telescopes, coupled with methane's short lifetime in the martian atmosphere, may imply an active gas source in the planet's subsurface, with migration and surface emission processes similar to those known on Earth as “gas seepage.” Here, we review the variety of subsurface processes that could result in methane seepage on Mars. Such methane could originate from abiotic chemical reactions, thermogenic alteration of abiotic or biotic organic matter, and ancient or extant microbial metabolism. These processes can occur over a wide range of temperatures, in both sedimentary and igneous rocks, and together they enhance the possibility that significant amounts of methane could have formed on early Mars. Methane seepage to the surface would occur preferentially along faults and fractures, through focused macro-seeps and/or diffuse microseepage exhalations. Our work highlights the types of features on Mars that could be associated with methane release, including mud-volcano-like mounds in Acidalia or Utopia; proposed ancient springs in Gusev Crater, Arabia Terra, and Valles Marineris; and rims of large impact craters. These could have been locations of past macro-seeps and may still emit methane today. Microseepage could occur through faults along the dichotomy or fractures such as those at Nili Fossae, Cerberus Fossae, the Argyre impact, and those produced in serpentinized rocks. Martian microseepage would be extremely difficult to detect remotely yet could constitute a significant gas source. We emphasize that the most definitive detection of methane seepage from different release candidates would be best provided by measurements performed in the ground or at the ground-atmosphere interface by landers or rovers and that the technology for such detection is currently available. Key Words: Mars—Methane—Seepage—Clathrate—Fischer-Tropsch—Serpentinization. Astrobiology 17, 1233–1264. PMID:28771029

Methane Emissions From Western Siberian Wetlands: Heterogeneity and Sensitivity to Climate Change

NASA Astrophysics Data System (ADS)

Bohn, T. J.; Lettenmaier, D. P.; Podest, E.; McDonald, K. C.; Sathulur, K.; Bowling, L. C.; Friborg, T.

2007-12-01

Prediction of methane emissions from high-latitude wetlands is important given concerns about their sensitivity to a warming climate. As a basis for prediction of wetland methane emissions at regional scales, we have coupled the Variable Infiltration Capacity macroscale hydrological model (VIC) with the Biosphere-Energy-Transfer- Hydrology terrestrial ecosystem model (BETHY) and a wetland methane emissions model to make large-scale estimates of methane emissions as a function of soil temperature, water table depth, and net primary productivity (NPP), with a parameterization of the sub-grid heterogeneity of the water table depth based on topographic wetness index. Using landcover classifications derived from L-band satellite synthetic aperture radar imagery, we simulated methane emissions for the Chaya River basin in western Siberia, an area that includes the Bakchar Bog, for a retrospective baseline period of 1980-1999, and evaluated their sensitivity to increases in temperature of 0-5 °C and increases in precipitation of 0-15%. The interactions of temperature and precipitation, through their effects on the water table depth, play an important role in determining methane emissions from these wetlands. The balance between these effects varies spatially, and their net effect depends in part on sub- grid topographic heterogeneity. Higher temperatures alone increase methane production in saturated areas, but cause those saturated areas to shrink in extent, resulting in a net reduction in methane emissions. Higher precipitation alone raises water tables and expands the saturated area, resulting in a net increase in methane emissions. Combining a temperature increase of 3 °C and an increase of 10% in precipitation, to represent the climate conditions likely in western Siberia at the end of this century, results in roughly a doubling of annual methane emissions. This work was carried out at the University of Washington, at Purdue University, and at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

Heritage and Advanced Technology Systems Engineering Lessons Learned from NASA Space Missions

NASA Technical Reports Server (NTRS)

Barley, Bryan; Newhouse, Marilyn; Bacskay, Allen

2010-01-01

Use of heritage and new technology is necessary/enabling to implementing small, low cost missions, yet overruns decrease the ability to sustain future mission flight rates The majority of the cost growth drivers seen in the D&NF study were embedded early during formulation phase and later realized during the development and I&T phases Cost drivers can be avoided or significantly decreased by project management and SE emphasis on early identification of risks and realistic analyses SE processes that emphasize an assessment of technology within the mission system to identify technical issues in the design or operational use of the technology. Realistic assessment of new and heritage spacecraft technology assumptions , identification of risks and mitigation strategies. Realistic estimates of effort required to inherit existing or qualify new technology, identification of risks to estimates and develop mitigation strategies. Allocation of project reserves for risk-based mitigation strategies of each individual area of heritage or new technology. Careful tailoring of inheritance processes to ensure due diligence.

Environmental risks of the gas hydrate field development in the Eastern Nankai Trough

NASA Astrophysics Data System (ADS)

Yamamoto, K.; Nagakubo, S.

2009-12-01

To establish any kinds of new energy resources, environmental impacts of the technology should be well understood before full industrial implementation. Methane hydrate (MH), a relatively clean fossil energy with low CO2 and no SOx emission, is not an exception. Because methane gas itself has strong greenhouse gas effect, and methane hydrate is not stable under the atmospheric pressure and room temperature, public image of MH field development is very risky game and potentially disastrous to the global climate. However, the real physics of the MH bearing sediments is far different from such images. MH21 Research Consortium in Japan has studied about the resource assessment and production techniques to develop MH since 2001. As the results, we found several gas hydrate concentrated zones with pore filling type hydrate in sandy layers of turbidite sediment in the Eastern Nankai Trough area off coasts of the Central Japan. The depressurization technique, in the other word, in-situ MH dissociation by water production and natural heat supply from surrounding formation, will be used as the basic method to produce methane gas from MH. Under the conditions, we have evaluated realistic environmental risk of the MH production. Because the most MH found in the Eastern Nankai Trough are composed of biogenic and almost pure methane, there is no concern of sea water contamination by oil releases that is the most common environmental disaster caused by misconducts of the oil industry. Also MH reservoirs there are not pressurized, and blowout of wells during drilling is very unlikely. Endothermic MH dissociation process decreases formation temperature with depressurization, and give negative feedback, then, there is no chance of chain reaction. Heat supply from surrounding formations is necessary for continuous dissociation, but heat transfer in the formations is relatively slow, and the dissociation rate is limited. Once the operation to pump water in boreholes for depressurization is stopped, or some troubles break surface facilities, pressure recovers to the original condition, but formation temperature is kept low by inflow of cold sea water. Therefore, the gas release risk of the offshore MH field is lower than conventional oil and gas. There can be a slight chance to release gas to seafloor after the production along with pressure recovery though natural and man-made pathways such as poorly abandoned wells, reactivated fractures or faults, etc. Even in the case, most of the discharged gas will be dissolved in to seawater, and almost no chance to discharge it into atmosphere. Another possible scenario is surface instability caused by weakened formation due to MH dissociation. To mitigate the risk to avoid catastrophic phenomena, site selection is the key. During the offshore production tests planned in 2012 and 2014, MH21 will conduct modelling, monitoring and verification program to quantify the real environmental risks of the MH field development.

From Fundamental Understanding To Predicting New Nanomaterials For High Capacity Hydrogen/Methane Storage and Carbon Capture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yildirim, Taner

2015-03-03

On-board hydrogen/methane storage in fuel cell-powered vehicles is a major component of the national need to achieve energy independence and protect the environment. The main obstacles in hydrogen storage are slow kinetics, poor reversibility and high dehydrogenation temperatures for the chemical hydrides; and very low desorption temperatures/energies for the physisorption materials (MOF’s, porous carbons). Similarly, the current methane storage technologies are mainly based on physisorption in porous materials but the gravimetric and volumetric storage capacities are below the target values. Finally, carbon capture, a critical component of the mitigation of CO2 emissions from industrial plants, also suffers from similar problems.more » The solid-absorbers such as MOFs are either not stable against real flue-gas conditions and/or do not have large enough CO2 capture capacity to be practical and cost effective. In this project, we addressed these challenges using a unique combination of computational, synthetic and experimental methods. The main scope of our research was to achieve fundamental understanding of the chemical and structural interactions governing the storage and release of hydrogen/methane and carbon capture in a wide spectrum of candidate materials. We studied the effect of scaffolding and doping of the candidate materials on their storage and dynamics properties. We reviewed current progress, challenges and prospect in closely related fields of hydrogen/methane storage and carbon capture.[1-5] For example, for physisorption based storage materials, we show that tap-densities or simply pressing MOFs into pellet forms reduce the uptake capacities by half and therefore packing MOFs is one of the most important challenges going forward. For room temperature hydrogen storage application of MOFs, we argue that MOFs are the most promising scaffold materials for Ammonia-Borane (AB) because of their unique interior active metal-centers for AB binding and well defined and ordered pores. Here the main challenge is to find a chemically stable MOF required for regeneration of the AB-spent fuel. Finally, for carbon capture application of MOFs, we investigate the performance of a number of metal–organic frameworks with particular focus on their behavior at the low pressures commonly used in swing adsorption. This comparison clearly shows that it is the process that determines which MOF is optimal rather than there being one best MOF, though MOFs that possess enhanced binding at open metal sites generally perform better than those with high surface area. References: 1. Y. Peng, V. Krungleviciute, J. T. Hupp, O. K. Farha, and T. Yildirim, J. Am. Chem. Soc. 135, 11887 (2013). 2. G. Srinivas, V. Krungleviciute, Z. Guo, and T. Yildirim, Ener. Environ. Sci. 7, 335 (2014). 3. G. Burres, and T. Yildirim, Ener. Environ. Sci. 5, 6453 (2012). 4. G. Srinivas, W. Travis, J. Ford, H. Wu, Z. X. Guo, and T. Yildirim, J. Mat. Chem.1, 4167 (2013). 5. For details, please see http://www.ncnr.nist.gov/staff/taner« less

Super-emitters in natural gas infrastructure are caused by abnormal process conditions

NASA Astrophysics Data System (ADS)

Zavala-Araiza, Daniel; Alvarez, Ramón A.; Lyon, David R.; Allen, David T.; Marchese, Anthony J.; Zimmerle, Daniel J.; Hamburg, Steven P.

2017-01-01

Effectively mitigating methane emissions from the natural gas supply chain requires addressing the disproportionate influence of high-emitting sources. Here we use a Monte Carlo simulation to aggregate methane emissions from all components on natural gas production sites in the Barnett Shale production region (Texas). Our total emission estimates are two-thirds of those derived from independent site-based measurements. Although some high-emitting operations occur by design (condensate flashing and liquid unloadings), they occur more than an order of magnitude less frequently than required to explain the reported frequency at which high site-based emissions are observed. We conclude that the occurrence of abnormal process conditions (for example, malfunctions upstream of the point of emissions; equipment issues) cause additional emissions that explain the gap between component-based and site-based emissions. Such abnormal conditions can cause a substantial proportion of a site's gas production to be emitted to the atmosphere and are the defining attribute of super-emitting sites.

Rumen microbial community composition varies with diet and host, but a core microbiome is found across a wide geographical range

PubMed Central

Henderson, Gemma; Cox, Faith; Ganesh, Siva; Jonker, Arjan; Young, Wayne; Abecia, Leticia; Angarita, Erika; Aravena, Paula; Nora Arenas, Graciela; Ariza, Claudia; Attwood, Graeme T.; Mauricio Avila, Jose; Avila-Stagno, Jorge; Bannink, André; Barahona, Rolando; Batistotti, Mariano; Bertelsen, Mads F.; Brown-Kav, Aya; Carvajal, Andres M.; Cersosimo, Laura; Vieira Chaves, Alexandre; Church, John; Clipson, Nicholas; Cobos-Peralta, Mario A.; Cookson, Adrian L.; Cravero, Silvio; Cristobal Carballo, Omar; Crosley, Katie; Cruz, Gustavo; Cerón Cucchi, María; de la Barra, Rodrigo; De Menezes, Alexandre B.; Detmann, Edenio; Dieho, Kasper; Dijkstra, Jan; dos Reis, William L. S.; Dugan, Mike E. R.; Hadi Ebrahimi, Seyed; Eythórsdóttir, Emma; Nde Fon, Fabian; Fraga, Martín; Franco, Francisco; Friedeman, Chris; Fukuma, Naoki; Gagić, Dragana; Gangnat, Isabelle; Javier Grilli, Diego; Guan, Le Luo; Heidarian Miri, Vahideh; Hernandez-Sanabria, Emma; Gomez, Alma Ximena Ibarra; Isah, Olubukola A.; Ishaq, Suzanne; Jami, Elie; Jelincic, Juan; Kantanen, Juha; Kelly, William J.; Kim, Seon-Ho; Klieve, Athol; Kobayashi, Yasuo; Koike, Satoshi; Kopecny, Jan; Nygaard Kristensen, Torsten; Julie Krizsan, Sophie; LaChance, Hannah; Lachman, Medora; Lamberson, William R.; Lambie, Suzanne; Lassen, Jan; Leahy, Sinead C.; Lee, Sang-Suk; Leiber, Florian; Lewis, Eva; Lin, Bo; Lira, Raúl; Lund, Peter; Macipe, Edgar; Mamuad, Lovelia L.; Cuquetto Mantovani, Hilário; Marcoppido, Gisela Ariana; Márquez, Cristian; Martin, Cécile; Martinez, Gonzalo; Eugenia Martinez, Maria; Lucía Mayorga, Olga; McAllister, Tim A.; McSweeney, Chris; Mestre, Lorena; Minnee, Elena; Mitsumori, Makoto; Mizrahi, Itzhak; Molina, Isabel; Muenger, Andreas; Munoz, Camila; Murovec, Bostjan; Newbold, John; Nsereko, Victor; O’Donovan, Michael; Okunade, Sunday; O’Neill, Brendan; Ospina, Sonia; Ouwerkerk, Diane; Parra, Diana; Pereira, Luiz Gustavo Ribeiro; Pinares-Patino, Cesar; Pope, Phil B.; Poulsen, Morten; Rodehutscord, Markus; Rodriguez, Tatiana; Saito, Kunihiko; Sales, Francisco; Sauer, Catherine; Shingfield, Kevin; Shoji, Noriaki; Simunek, Jiri; Stojanović-Radić, Zorica; Stres, Blaz; Sun, Xuezhao; Swartz, Jeffery; Liang Tan, Zhi; Tapio, Ilma; Taxis, Tasia M.; Tomkins, Nigel; Ungerfeld, Emilio; Valizadeh, Reza; van Adrichem, Peter; Van Hamme, Jonathan; Van Hoven, Woulter; Waghorn, Garry; John Wallace, R.; Wang, Min; Waters, Sinéad M.; Keogh, Kate; Witzig, Maren; Wright, Andre-Denis G.; Yamano, Hidehisa; Yan, Tianhai; Yanez-Ruiz, David R.; Yeoman, Carl J.; Zambrano, Ricardo; Zeitz, Johanna; Zhou, Mi; Wei Zhou, Hua; Xia Zou, Cai; Zunino, Pablo; Janssen, Peter H.

2015-01-01

Ruminant livestock are important sources of human food and global greenhouse gas emissions. Feed degradation and methane formation by ruminants rely on metabolic interactions between rumen microbes and affect ruminant productivity. Rumen and camelid foregut microbial community composition was determined in 742 samples from 32 animal species and 35 countries, to estimate if this was influenced by diet, host species, or geography. Similar bacteria and archaea dominated in nearly all samples, while protozoal communities were more variable. The dominant bacteria are poorly characterised, but the methanogenic archaea are better known and highly conserved across the world. This universality and limited diversity could make it possible to mitigate methane emissions by developing strategies that target the few dominant methanogens. Differences in microbial community compositions were predominantly attributable to diet, with the host being less influential. There were few strong co-occurrence patterns between microbes, suggesting that major metabolic interactions are non-selective rather than specific. PMID:26449758

Accumulation of propionic acid during consecutive batch anaerobic digestion of commercial food waste.

PubMed

Capson-Tojo, Gabriel; Ruiz, Diane; Rouez, Maxime; Crest, Marion; Steyer, Jean-Philippe; Bernet, Nicolas; Delgenès, Jean-Philippe; Escudié, Renaud

2017-12-01

The objective of this study was to test three different alternatives to mitigate the destabilizing effect of accumulation of ammonia and volatile fatty acids during food waste anaerobic digestion. The three options tested (low temperature, co-digestion with paper waste and trace elements addition) were compared using consecutive batch reactors. Although methane was produced efficiently (∼500ml CH 4 gVS -1 ; 16l CH 4 lreactor -1 ), the concentrations of propionic acid increased gradually (up to 21.6gl -1 ). This caused lag phases in the methane production and eventually led to acidification at high substrate loads. The addition of trace elements improved the kinetics and allowed higher substrate loads, but could not avoid propionate accumulation. Here, it is shown for the first time that addition of activated carbon, trace elements and dilution can favor propionic acid consumption after its accumulation. These promising options should be optimized to prevent propionate accumulation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Can sediments at hydrocarbon seep sites represent a source for marine bioavailable iron? — A case study from the South China Sea

NASA Astrophysics Data System (ADS)

Li, N.; Feng, D.; Chen, D.

2017-12-01

Niu Li1, Dong Feng1,2, and Duofu Chen2,31CAS Key Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China. 2Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266061, China. 3Hadal Science and Technology Research Center, College of Marine Sciences, Shanghai Ocean University, Shanghai 201306, China. Iron is an essential micronutrient and commonly considered to be one of the key-limiting factors for biological productivity in many ocean regions. Seafloor Fe supply should be most efficient in suboxic conditions. Recent studies shown that widely spread anoxic environments can develop in hydrocarbon seep sediment and local bottom water, owing to the occurrence of aerobic and/or anaerobic methane oxidation. Under this condition, the iron in sediment can be reduced to dissolved Fe2+ in the ocean. However, questions remain about whether the hydrocarbon seep sediment can represent a source for bioavailable iron to the ocean, and the control factor for the transformation of iron in the sediment remains largely unexplored. For a number of hydrocarbon seeps from the northern and southern South China Sea, the iron speciation, pyrite sulfur isotope, and iron isotope, as well as the major and trace elements are used to constrain the intensity of cold seep, and its impact on transformation of iron in sediment. Samples from both areas show sediment iron lost during the high methane flux conditions, owing to the suboxic conditions cause by aerobic methane oxidation. On the other hand, high sediment iron content accompanied by high sulfur content can be seen during the conditions of high methane flux without the occurrence of aerobic methane oxidation, which is possible ascribed to the anaerobic methane oxidation and the release of iron through seep activity. This study reveals the transformation of iron in the sediment is closely related to the methane flux and the hydrocarbon seep sediment can represent a source for bioavailable iron to the ocean. Acknowledgments: Funding was provided by the NSF of China (Grants: 41422602 and 41373085).

Crosscutting Airborne Remote Sensing Technologies for Oil and Gas and Earth Science Applications

NASA Technical Reports Server (NTRS)

Aubrey, A. D.; Frankenberg, C.; Green, R. O.; Eastwood, M. L.; Thompson, D. R.; Thorpe, A. K.

2015-01-01

Airborne imaging spectroscopy has evolved dramatically since the 1980s as a robust remote sensing technique used to generate 2-dimensional maps of surface properties over large spatial areas. Traditional applications for passive airborne imaging spectroscopy include interrogation of surface composition, such as mapping of vegetation diversity and surface geological composition. Two recent applications are particularly relevant to the needs of both the oil and gas as well as government sectors: quantification of surficial hydrocarbon thickness in aquatic environments and mapping atmospheric greenhouse gas components. These techniques provide valuable capabilities for petroleum seepage in addition to detection and quantification of fugitive emissions. New empirical data that provides insight into the source strength of anthropogenic methane will be reviewed, with particular emphasis on the evolving constraints enabled by new methane remote sensing techniques. Contemporary studies attribute high-strength point sources as significantly contributing to the national methane inventory and underscore the need for high performance remote sensing technologies that provide quantitative leak detection. Imaging sensors that map spatial distributions of methane anomalies provide effective techniques to detect, localize, and quantify fugitive leaks. Airborne remote sensing instruments provide the unique combination of high spatial resolution (<1 m) and large coverage required to directly attribute methane emissions to individual emission sources. This capability cannot currently be achieved using spaceborne sensors. In this study, results from recent NASA remote sensing field experiments focused on point-source leak detection, will be highlighted. This includes existing quantitative capabilities for oil and methane using state-of-the-art airborne remote sensing instruments. While these capabilities are of interest to NASA for assessment of environmental impact and global climate change, industry similarly seeks to detect and localize leaks of both oil and methane across operating fields. In some cases, higher sensitivities desired for upstream and downstream applications can only be provided by new airborne remote sensing instruments tailored specifically for a given application. There exists a unique opportunity for alignment of efforts between commercial and government sectors to advance the next generation of instruments to provide more sensitive leak detection capabilities, including those for quantitative source strength determination.

Development of Augmented Spark Impinging Igniter System for Methane Engines

NASA Technical Reports Server (NTRS)

Marshall, William M.; Osborne, Robin J.; Greene, Sandra E.

2017-01-01

The Lunar Cargo Transportation and Landing by Soft Touchdown (Lunar CATALYST) program is establishing multiple no-funds-exchanged Space Act Agreement (SAA) partnerships with U.S. private sector entities. The purpose of this program is to encourage the development of robotic lunar landers that can be integrated with U.S. commercial launch capabilities to deliver payloads to the lunar surface. As part of the efforts in Lander Technologies, NASA Marshall Space Flight Center (MSFC) is developing liquid oxygen (LOX) and liquid methane (LCH4) engine technology to share with the Lunar CATALYST partners. Liquid oxygen and liquid methane propellants are attractive owing to their relatively high specific impulse for chemical propulsion systems, modest storage requirements, and adaptability to NASA's Journey to Mars plans. Methane has also been viewed as a possible propellant choice for lunar missions, owing to the performance benefits and as a technology development stepping stone to Martian missions. However, in the development of methane propulsion, methane ignition has historically been viewed as a high risk area in the development of such an engine. A great deal of work has been conducted in the past decade devoted to risk reduction in LOX/CH4 ignition. This paper will review and summarize the history and results of LOX/CH4 ignition programs conducted at NASA. More recently, a NASA-developed Augmented Spark Impinging (ASI) igniter body, which utilizes a conventional spark exciter system, is being tested with LOX/CH4 to help support internal and commercial engine development programs, such as those in Lunar CATALYST. One challenge with spark exciter systems, especially at altitude conditions, is the ignition lead that transmits the high voltage pulse from the exciter to the spark igniter (spark plug). The ignition lead can be prone to corona discharge, reducing the energy delivered by the spark and potentially causing non-ignition events. For the current work, a commercial compact exciter system, which eliminates this high voltage cabling, was tested at altitude conditions. A modified, conventional exciter system with an improved ignition lead was also recently tested at altitude conditions. This test program demonstrated the capability of these exciter systems to operate at altitude. While more extensive testing may be required, these systems or similar ones may be used for future NASA and commercial engine programs.

Impact of Real-world Factors Influencing Investment Decisions on the Costs and Distribution of Climate Change Mitigation

NASA Astrophysics Data System (ADS)

Edmonds, J.; Iyer, G.; McJeon, H. C.; Leon, C.; Hultman, N.

2015-12-01

Strategies to mitigate dangerous anthropogenic climate change require a dramatic transformation of the energy system to reduce greenhouse gas emissions, that in turn requires large-scale investments. Investment decisions depend not only on investment capital availability but also on investment risks. A number of factors such as national policy environments, quality of public and private institutions, sector, firm and technology specific characteristics can affect investors' assessments of risks, leading to a wide variation in the business climate for investment. Such heterogeneity in investment risks can have important implications, as investors usually respond to risks by requiring higher returns for riskier projects; delaying or forgoing the investments; or preferring to invest in existing, familiar projects. We study the impact of variation in investment risks on regional patterns of emissions mitigation, the cost of emissions mitigation and patterns of technology deployment. We modify an integrated assessment model, widely used in global climate policy analyses (the Global Change Assessment Model) and incorporate decisions on investments based on risks along two dimensions. Along the first dimension, we vary perceived risks associated with particular technologies. To do so, we assign a higher cost of capital for investment in low-carbon technologies as these involve intrinsically higher levels of regulatory and market risk. The second dimension uses a proxy to vary investment risks across regions, based on an institutional quality metric published by the World Economic Forum. Explicit representation of investment risks has two major effects. First, it raises the cost of emissions mitigation relative to a world with uniform investment risks. Second, it shifts the pattern of emissions mitigation, with industrialized countries mitigating more, and developing countries mitigating less. Our results suggest that institutional reforms aimed at lowering investment risks could be an important element in lowering the cost of climate change mitigation solutions.

Open Path Trace Gas Laser Sensors for UAV Deployment

NASA Astrophysics Data System (ADS)

Shadman, S.; Mchale, L.; Rose, C.; Yalin, A.

2015-12-01

Novel trace gas sensors based on open-path Cavity Ring-down Spectroscopy (CRDS) are being developed to enable remote and mobile deployments including on small unmanned aerial systems (UAS). Relative to established closed-path CRDS instruments, the use of open-path configurations allows removal of the bulky and power hungry vacuum and flow system, potentially enabling lightweight and low power instruments with high sensitivity. However, open path operation introduces new challenges including the need to maintain mirror cleanliness, mitigation of particle optical effects, and the need to measure spectral features that are relatively broad. The present submission details open-path CRDS instruments for ammonia and methane and their planned use in UAS studies. The ammonia sensor uses a quantum cascade laser at 10.3 mm in a configuration in which the laser frequency is continuously swept and a trigger circuit and acousto-optic modulator (AOM) extinguish the light when the laser is resonant with the cavity. Ring-down signals are measured with a two-stage thermoelectrically cooled MCT photodetector. The cavity mirrors have reflectivity of 0.9995 and a noise equivalent absorption of 1.5 ppb Hz-1/2 was demonstrated. A first version of the methane sensor operated at 1.7um with a telecom diode laser while the current version operates at 3.6 um with an interband cascade laser (stronger absorption). We have performed validation measurements against known standards for both sensors. Compact optical assemblies are being developed for UAS deployment. For example, the methane sensor head will have target mass of <4 kg and power draw <40 W. A compact single board computer and DAQ system is being designed for sensor control and signal processing with target mass <1 kg and power draw <10 W. The sensor size and power parameters are suitable for UAS deployment on both fixed wing and rotor style UAS. We plan to deploy the methane sensor to measure leakage and emission of methane from natural gas infrastructure, and to deploy both sensors together to study emissions from dairies and feedlots. The latter measurement campaign will also examine ammonia deposition to the ground, and bi-directional ammonia fluxes, using methane as a conservative tracer and examining the change in the ratio of ammonia to methane as a function of downwind position.

Mitigation of methane production from cattle by feeding cashew nut shell liquid.

PubMed

Shinkai, T; Enishi, O; Mitsumori, M; Higuchi, K; Kobayashi, Y; Takenaka, A; Nagashima, K; Mochizuki, M; Kobayashi, Y

2012-09-01

The effects of cashew nut shell liquid (CNSL) feeding on methane production and rumen fermentation were investigated by repeatedly using 3 Holstein nonlactating cows with rumen fistulas. The cows were fed a concentrate and hay diet (6:4 ratio) for 4 wk (control period) followed by the same diet with a CNSL-containing pellet for the next 3 wk (CNSL period). Two trials were conducted using CNSL pellets blended with only silica (trial 1) or with several other ingredients (trial 2). Each pellet type was fed to cows to allow CNSL intake at 4 g/100 kg of body weight per day. Methane production was measured in a respiration chamber system, and energy balance, nutrient digestibility, and rumen microbial changes were monitored. Methane production per unit of dry matter intake decreased by 38.3 and 19.3% in CNSL feeding trials 1 and 2, respectively. Energy loss as methane emission decreased from 9.7 to 6.1% (trial 1) and from 8.4 to 7.0% (trial 2) with CNSL feeding, whereas the loss to feces (trial 1) and heat production (trial 2) increased. Retained energy did not differ between the control and CNSL periods. Digestibility of dry matter and gross energy decreased with CNSL feeding in trial 1, but did not differ in trial 2. Feeding CNSL caused a decrease in acetate and total short-chain fatty acid levels and an increase in propionate proportion in both trials. Relative copy number of methyl coenzyme-M reductase subunit A gene and its expression decreased with CNSL feeding. The relative abundance of fibrolytic or formate-producing species such as Ruminococcus flavefaciens, Butyrivibrio fibrisolvens, and Treponema bryantii decreased, but species related to propionate production, including Prevotella ruminicolla, Selenomonas ruminantium, Anaerovibrio lipolytica, and Succinivibrio dextrinosolvens, increased. If used in a suitable formulation, CNSL acts as a potent methane-inhibiting and propionate-enhancing agent through the alteration of rumen microbiota without adversely affecting feed digestibility. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Hydropower's Biogenic Carbon Footprint

PubMed Central

Pfister, Stephan

2016-01-01

Global warming is accelerating and the world urgently needs a shift to clean and renewable energy. Hydropower is currently the largest renewable source of electricity, but its contribution to climate change mitigation is not yet fully understood. Hydroelectric reservoirs are a source of biogenic greenhouse gases and in individual cases can reach the same emission rates as thermal power plants. Little is known about the severity of their emissions at the global scale. Here we show that the carbon footprint of hydropower is far higher than previously assumed, with a global average of 173 kg CO2 and 2.95 kg CH4 emitted per MWh of electricity produced. This results in a combined average carbon footprint of 273 kg CO2e/MWh when using the global warming potential over a time horizon of 100 years (GWP100). Nonetheless, this is still below that of fossil energy sources without the use of carbon capture and sequestration technologies. We identified the dams most promising for capturing methane for use as alternative energy source. The spread among the ~1500 hydropower plants analysed in this study is large and highlights the importance of case-by-case examinations. PMID:27626943

Anaerobic treatment of distillery spent wash - a study on upflow anaerobic fixed film bioreactor.

PubMed

Acharya, Bhavik K; Mohana, Sarayu; Madamwar, Datta

2008-07-01

Anaerobic digestion of wastewater from a distillery industry having very high COD (1,10,000-1,90,000 mg/L) and BOD (50,000-60,000 mg/L) was studied in a continuously fed, up flow fixed film column reactor using different support materials such as charcoal, coconut coir and nylon fibers under varying hydraulic retention time and organic loading rates. The seed consortium was prepared by enrichment with distillery spent wash in a conventional type reactor having working capacity of 3 L and was used for charging the anaerobic column reactor. Amongst the various support materials studied the reactor having coconut coir could treat distillery spent wash at 8d hydraulic retention time with organic loading rate of 23.25 kg COD m(-3)d(-1) leading to 64% COD reduction with biogas production of 7.2 m3 m(-3)d(-1) having high methane yield without any pretreatment or neutralization of the distillery spent wash. This study indicates fixed film biomethanation of distillery spent wash using coconut coir as the support material appears to be a cost effective and promising technology for mitigating the problems caused by distillery effluent.

Liquid Oxygen/Liquid Methane Ascent Main Engine Technology Development

NASA Technical Reports Server (NTRS)

Robinson, Joel W.; Stephenson, David D.

2008-01-01

The National Aeronautics & Space Administration (NASA) has identified Liquid Oxygen (LO2)/Liquid Methane (LCH4) as a potential propellant combination for future space vehicles based upon the Exploration Systems Architecture Study (ESAS). The technology is estimated to have higher performance and lower overall systems mass compared to existing hypergolic propulsion systems. The current application considering this technology is the lunar ascent main engine (AME). AME is anticipated to be an expendable, pressure-fed engine to provide ascent from the moon at the completion of a 210 day lunar stay. The engine is expected to produce 5,500 lbf (24,465 N) thrust with variable inlet temperatures due to the cryogenic nature of the fuel and oxidizer. The primary technology risks include establishing reliable and robust ignition in vacuum conditions, maximizing specific impulse, developing rapid start capability for the descent abort, providing the capability for two starts and producing a total engine bum time over 500 seconds. This paper will highlight the efforts of the Marshall Space Flight Center (MSFC) in addressing risk reduction activities for this technology.

Need for improvements in physical pretreatment of source-separated household food waste.

PubMed

Bernstad, A; Malmquist, L; Truedsson, C; la Cour Jansen, J

2013-03-01

The aim of the present study was to investigate the efficiency in physical pretreatment processes of source-separated solid organic household waste. The investigation of seventeen Swedish full-scale pretreatment facilities, currently receiving separately collected food waste from household for subsequent anaerobic digestion, shows that problems with the quality of produced biomass and high maintenance costs are common. Four full-scale physical pretreatment plants, three using screwpress technology and one using dispergation technology, were compared in relation to resource efficiency, losses of nitrogen and potential methane production from biodegradable matter as well as the ratio of unwanted materials in produced biomass intended for wet anaerobic digestion. Refuse generated in the processes represent 13-39% of TS in incoming wet waste. The methane yield from these fractions corresponds to 14-36Nm(3)/ton separately collected solid organic household waste. Also, 13-32% of N-tot in incoming food waste is found in refuse. Losses of both biodegradable material and nutrients were larger in the three facilities using screwpress technology compared to the facility using dispersion technology.(1) Thus, there are large potentials for increase of both the methane yield and nutrient recovery from separately collected solid organic household waste through increased efficiency in facilities for physical pretreatment. Improved pretreatment processes could thereby increase the overall environmental benefits from anaerobic digestion as a treatment alternative for solid organic household waste. Copyright © 2012 Elsevier Ltd. All rights reserved.

Assessing Distribution and Origin of Methane in Shallow Groundwater in Horizontal Oil and Gas Play Areas, Eastern Kentucky

NASA Astrophysics Data System (ADS)

Zhu, J.; Parris, T. M.; Taylor, C. J.; Webb, S. E.; Davidson, B.; Smath, R.; Richardson, S. D.; Molofsky, L.; Kromann, J. S.

2016-12-01

Rapid implementation of horizontal drilling and hydraulic fracturing technology to produce oil and gas from tight rock formations across the country has increased public concern about possible impact on the environment, especially on shallow drinking-water aquifers. In eastern Kentucky, horizontal drilling and hydraulic fracturing have been used to develop the Upper Devonian Berea Sandstone in recent years. Although production in the Berea Sandstone is at a relatively small scale, the Rogersville Shale, a deeper, thicker, and more spatially extensive organic-rich shale, is projected to become a major shale play in eastern Kentucky. This has necessitated a better understanding of groundwater quality, especially the occurrence of dissolved methane, in aquifers overlying the Berea and Rogersville plays to help address the public's environmental concerns and protect groundwater resources. To assess baseline groundwater chemistry and evaluate distribution and origin of methane detected in the groundwater, 51 water wells in Greenup, Carter, Boyd, Lawrence, Johnson, and Elliott Counties were sampled and analyzed for major cations and anions, metals, and dissolved light hydrocarbon gases including methane. Twenty-six wells were identified as having methane concentrations greater than 1 mg/L and were further analyzed for carbon and hydrogen isotopes. The results indicate that methane is a relatively common constituent in shallow groundwater in eastern Kentucky. Correlation of methane distribution with water chemistry data shows that elevated methane concentrations were more common in sodium bicarbonate type water and in low-nitrate, low-sulfate redox conditions. Carbon and hydrogen isotope analysis suggests that the methane detected in groundwater is derived primarily from bacterial sources from the CO2 reduction pathway.

Method of gas emission control for safe working of flat gassy coal seams

NASA Astrophysics Data System (ADS)

Vinogradov, E. A.; Yaroshenko, V. V.; Kislicyn, M. S.

2017-10-01

The main problems at intensive flat gassy coal seam longwall mining are considered. For example, mine Kotinskaja JSC “SUEK-Kuzbass” shows that when conducting the work on the gassy coal seams, methane emission control by means of ventilation, degassing and insulated drain of methane-air mixture is not effective and stable enough. It is not always possible to remove the coal production restrictions by the gas factor, which leads to financial losses because of incomplete using of longwall equipment and the reduction of the technical and economic indicators of mining. To solve the problems, the authors used a complex method that includes the compilation and analysis of the theory and practice of intensive flat gassy coal seam longwall mining. Based on the results of field and numerical researches, the effect of parameters of technological schemes on efficiency of methane emission control on longwall panels, the non-linear dependence of the permissible according to gas factor longwall productivity on parameters of technological schemes, ventilation and degassing during intensive mining flat gassy coal seams was established. The number of recommendations on the choice of the location and the size of the intermediate section of coal heading to control gassing in the mining extracted area, and guidelines for choosing the parameters of ventilation of extracted area with the help of two air supply entries and removal of isolated methane-air mixture are presented in the paper. The technological scheme, using intermediate entry for fresh air intake, ensuring effective management gassing and allowing one to refuse from drilling wells from the surface to the mined-out space for mining gas-bearing coal seams, was developed.

Simulation of natural gas production from submarine gas hydrate deposits combined with carbon dioxide storage

NASA Astrophysics Data System (ADS)

Janicki, Georg; Schlüter, Stefan; Hennig, Torsten; Deerberg, Görge

2013-04-01

The recovery of methane from gas hydrate layers that have been detected in several submarine sediments and permafrost regions around the world so far is considered to be a promising measure to overcome future shortages in natural gas as fuel or raw material for chemical syntheses. Being aware that natural gas resources that can be exploited with conventional technologies are limited, research is going on to open up new sources and develop technologies to produce methane and other energy carriers. Thus various research programs have started since the early 1990s in Japan, USA, Canada, South Korea, India, China and Germany to investigate hydrate deposits and develop technologies to destabilize the hydrates and obtain the pure gas. In recent years, intensive research has focussed on the capture and storage of carbon dioxide from combustion processes to reduce climate change. While different natural or manmade reservoirs like deep aquifers, exhausted oil and gas deposits or other geological formations are considered to store gaseous or liquid carbon dioxide, the storage of carbon dioxide as hydrate in former methane hydrate fields is another promising alternative. Due to beneficial stability conditions, methane recovery may be well combined with CO2 storage in form of hydrates. This has been shown in several laboratory tests and simulations - technical field tests are still in preparation. Within the scope of the German research project »SUGAR«, different technological approaches are evaluated and compared by means of dynamic system simulations and analysis. Detailed mathematical models for the most relevant chemical and physical effects are developed. The basic mechanisms of gas hydrate formation/dissociation and heat and mass transport in porous media are considered and implemented into simulation programs like CMG STARS and COMSOL Multiphysics. New simulations based on field data have been carried out. The studies focus on the evaluation of the gas production potential from turbidites and their ability for carbon dioxide storage. The effects occurring during gas production and CO2 storage within a hydrate deposit are identified and described for various scenarios. The behaviour of relevant process parameters such as pressure, temperature and phase saturations is discussed and compared for different production strategies: depressurization, CO2 injection after depressurization and simultaneous methane production and CO2 injection.

In Situ Bioremediation of 1,4-Dioxane by Methane Oxidizing Bacteria in Coupled Anaerobic-Aerobic Zones

DTIC Science & Technology

2016-02-11

groundwater in situ. Because of its low Koc and Henry’s Law constant, traditional remediation technologies such as carbon adsorption and air stripping...of 1,4-dioxane via methane oxidizing bacteria is of particular interest for in situ remedial purposes for two reasons. (1) Cometabolic mechanisms...2010. Final Remedial Action Report: Building 165 and Area 18C Groundwater Treatment Pilot Systems; Former Raritan Arsenal Project, Edison, NJ. US

Structural design of liquid oxygen/liquid methane robotic lander JANUS

NASA Astrophysics Data System (ADS)

Chaidez, Mariana

As the attempt to send humans to Mars has gained momentum in the last decade, the need to find alternative propellants that are safer, less toxic, and yields a better performance has become apparent [1]. Liquid methane and oxygen have emerged as a suitable alternative. In addition, the incorporation of liquid methane/liquid oxygen into the propulsion system has demonstrated an increase in engine performance, as well as a reduction in the volume, size and complexity of the propulsion system. In an attempt to further understand the technologies that are possible to develop using liquid oxygen (LO 2) and liquid methane (LCH4), a preliminary design of a robotic lander JANUS is being completed by the Center for Space Exploration and Technology Research (cSTER). The structural design of the vehicle is important because it acts as the skeleton of the vehicle and dictates the maneuverability of the robotic lander. To develop the structure of the robotic lander, six different design vehicle concepts with varying tank configurations were considered. Finite Element Analysis (FEA) was completed on each model to optimize each vehicle. Trade studies were completed to choose the best design for JANUS. Upon completion of the trade studies the design for the first prototype of JANUS was initiated in which the tank and thrust modules were designed. This thesis will describe the design process for the structural design of the JANUS.

The use of air bags for mitigating grade crossing and trespass accidents : literature review and research plan.

DOT National Transportation Integrated Search

2016-06-01

This literature review will confirm prior work in the use of locomotive airbag technologies for vehicle or pedestrian collision : mitigation, and to focus planned activities and tasks for this research. The state of the art in relevant technologies h...

Regeneratively Cooled Liquid Oxygen/Methane Technology Development Between NASA MSFC and PWR

NASA Technical Reports Server (NTRS)

Robinson, Joel W.; Greene, Christopher B.; Stout, Jeffrey B.

2012-01-01

The National Aeronautics & Space Administration (NASA) has identified Liquid Oxygen (LOX)/Liquid Methane (LCH4) as a potential propellant combination for future space vehicles based upon exploration studies. The technology is estimated to have higher performance and lower overall systems mass compared to existing hypergolic propulsion systems. NASA-Marshall Space Flight Center (MSFC) in concert with industry partner Pratt & Whitney Rocketdyne (PWR) utilized a Space Act Agreement to test an oxygen/methane engine system in the Summer of 2010. PWR provided a 5,500 lbf (24,465 N) LOX/LCH4 regenerative cycle engine to demonstrate advanced thrust chamber assembly hardware and to evaluate the performance characteristics of the system. The chamber designs offered alternatives to traditional regenerative engine designs with improvements in cost and/or performance. MSFC provided the test stand, consumables and test personnel. The hot fire testing explored the effective cooling of one of the thrust chamber designs along with determining the combustion efficiency with variations of pressure and mixture ratio. The paper will summarize the status of these efforts.

Dissolution of methane bubbles with hydrate armoring in deep ocean conditions

NASA Astrophysics Data System (ADS)

Kovalchuk, Margarita; Socolofsky, Scott

2017-11-01

The deep ocean is a storehouse of natural gas. Methane bubble moving upwards from marine sediments may become trapped in gas hydrates. It is uncertain precisely how hydrate armoring affects dissolution, or mass transfer from the bubble to the surrounding water column. The Texas A&M Oilspill Calculator was used to simulate a series of gas bubble dissolution experiments conducted in the United States Department of Energy National Energy Technology Laboratory High Pressure Water Tunnel. Several variations of the mass transfer coefficient were calculated based on gas or hydrate phase solubility and clean or dirty bubble correlations. Results suggest the mass transfer coefficient may be most closely modeled with gas phase solubility and dirty bubble correlation equations. Further investigation of hydrate bubble dissolution behavior will refine current numeric models which aid in understanding gas flux to the atmosphere and plumes such as oil spills. Research funded in part by the Texas A&M University 2017 Undergraduate Summer Research Grant and a Grant from the Methane Gas Hydrates Program of the US DOE National Energy Technology Laboratory.

Incubation Temperature, But Not Pequi Oil Supplementation, Affects Methane Production, and the Ruminal Microbiota in a Rumen Simulation Technique (Rusitec) System.

PubMed

Duarte, Andrea C; Holman, Devin B; Alexander, Trevor W; Kiri, Kerstin; Breves, Gerhard; Chaves, Alexandre V

2017-01-01

Lipid supplementation is a promising strategy for methane mitigation in cattle and has been evaluated using several different lipid sources. However, limited studies have assessed the effect of temperature on methane emissions from cattle and changes in incubation temperature have also not been extensively evaluated. The aim of this study was to evaluate the combined effect of pequi oil (high in unsaturated fatty acids) and incubation temperature on fermentation characteristics and microbial communities using the rumen simulation technique. A completely randomized experiment was conducted over a 28-day period using a Rusitec system. The experiment was divided into four periods of 7 days each, the first of which was a 7-day adaptation period followed by three experimental periods. The two treatments consisted of a control diet (no pequi oil inclusion) and a diet supplemented with pequi oil (1.5 mL/day) which increased the dietary fat content to 6% (dry matter, DM-basis). Three fermenter vessels (i.e., replicates) were allocated to each treatment. In the first experimental period, the incubation temperature was maintained at 39°C, decreased to 35°C in the second experimental period and then increased again to 39°C in the third. Pequi oil was continuously supplemented during the experiment. Microbial communities were assessed using high-throughput sequencing of the archaeal and bacterial 16S rRNA gene. Methane production was reduced by 57% following a 4°C decrease in incubation temperature. Supplementation with pequi oil increased the dietary fat content to 6% (DM-basis) but did not affect methane production. Analysis of the microbiota revealed that decreasing incubation temperature to 35°C affected the archaeal and bacterial diversity and richness of liquid-associated microbes, but lipid supplementation did not change microbial diversity.

The Effect of Dietary Replacement of Ordinary Rice with Red Yeast Rice on Nutrient Utilization, Enteric Methane Emission and Rumen Archaeal Diversity in Goats.

PubMed

Wang, L Z; Zhou, M L; Wang, J W; Wu, D; Yan, T

2016-01-01

Twenty castrated Boer crossbred goats were used in the present study with two treatments to examine the effect of dietary replacement of ordinary rice with red yeast rice on nutrient utilization, enteric methane emission and ruminal archaea structure and composition. Two treatment diets contained (DM basis) 70.0% of forage, 21.8% of concentrates and 8.2% of either ordinary rice (control) or red yeast rice (RYR). Nutrient utilization was measured and enteric methane emissions were determined in respiration chambers. Results showed that RYR had significantly lower digestibility of N and organic matter compared to control group. However, feeding red yeast rice did not affect N retention as g/d or a proportion of N intake, and reduced heat production as MJ/d or as a proportion of metabolizable energy intake, thus leading to a higher proportion of metabolizable energy intake to be retained in body tissue. RYR also had significantly lower methane emissions either as g/d, or as a proportion of feed intake. Although feeding red yeast rice had no negative effect on any rumen fermentation variables, it decreased serum contents of total cholesterol, triglycerides, HDL-cholesterol and LDL-cholesterol. In the present study, 75616 archaeal sequences were generated and clustered into 2364 Operational Taxonomic Units. At the genus level, the predominant archaea in the rumen of goats was Methanobrevibacter, which was significantly inhibited with the supplementation of red yeast rice. In conclusion, red yeast rice is a potential feed ingredient for mitigation of enteric methane emissions of goats. However, caution should be taken when it is used because it may inhibit the digestibility of some nutrients. Further studies are required to evaluate its potential with different diets and animal species, as well as its effects on animal health and food safety.

Low-cost lightweight airborne laser-based sensors for pipeline leak detection and reporting

NASA Astrophysics Data System (ADS)

Frish, Michael B.; Wainner, Richard T.; Laderer, Matthew C.; Allen, Mark G.; Rutherford, James; Wehnert, Paul; Dey, Sean; Gilchrist, John; Corbi, Ron; Picciaia, Daniele; Andreussi, Paolo; Furry, David

2013-05-01

Laser sensing enables aerial detection of natural gas pipeline leaks without need to fly through a hazardous gas plume. This paper describes adaptations of commercial laser-based methane sensing technology that provide relatively low-cost lightweight and battery-powered aerial leak sensors. The underlying technology is near-infrared Standoff Tunable Diode Laser Absorption Spectroscopy (sTDLAS). In one configuration, currently in commercial operation for pipeline surveillance, sTDLAS is combined with automated data reduction, alerting, navigation, and video imagery, integrated into a single-engine single-pilot light fixed-wing aircraft or helicopter platform. In a novel configuration for mapping landfill methane emissions, a miniaturized ultra-lightweight sTDLAS sensor flies aboard a small quad-rotor unmanned aerial vehicle (UAV).

Granular Carbon-Based Electrodes as Cathodes in Methane-Producing Bioelectrochemical Systems

PubMed Central

Liu, Dandan; Roca-Puigros, Marta; Geppert, Florian; Caizán-Juanarena, Leire; Na Ayudthaya, Susakul P.; Buisman, Cees; ter Heijne, Annemiek

2018-01-01

Methane-producing bioelectrochemical systems generate methane by using microorganisms to reduce carbon dioxide at the cathode with external electricity supply. This technology provides an innovative approach for renewable electricity conversion and storage. Two key factors that need further attention are production of methane at high rate, and stable performance under intermittent electricity supply. To study these key factors, we have used two electrode materials: granular activated carbon (GAC) and graphite granules (GG). Under galvanostatic control, the biocathodes achieved methane production rates of around 65 L CH4/m2catproj/d at 35 A/m2catproj, which is 3.8 times higher than reported so far. We also operated all biocathodes with intermittent current supply (time-ON/time-OFF: 4–2′, 3–3′, 2–4′). Current-to-methane efficiencies of all biocathodes were stable around 60% at 10 A/m2catproj and slightly decreased with increasing OFF time at 35 A/m2catproj, but original performance of all biocathodes was recovered soon after intermittent operation. Interestingly, the GAC biocathodes had a lower overpotential than the GG biocathodes, with methane generation occurring at −0.52 V vs. Ag/AgCl for GAC and at −0.92 V for GG at a current density of 10 A/m2catproj. 16S rRNA gene analysis showed that Methanobacterium was the dominant methanogen and that the GAC biocathodes experienced a higher abundance of proteobacteria than the GG biocathodes. Both cathode materials show promise for the practical application of methane-producing BESs. PMID:29946543

QuEST: Qualifying Environmentally Sustainable Technologies. Volume 6

NASA Technical Reports Server (NTRS)

Lewis, Pattie

2011-01-01

QuEST is a publication of the NASA Technology Evaluation for Environmental Risk Mitigation Principal Center (TEERM). This issue contains brief articles on: Risk Identification and Mitigation, Material Management and Substitution Efforts--Hexavalent Chrome-free Coatings and Low volatile organic compounds (VOCs) Coatings, Lead-Free Electronics, Corn-Based Depainting Media; Alternative Energy Efforts Hydrogen Sensors and Solar Air Conditioning. Other TEERM Efforts include: Energy and Water Management and Remediation Technology Collaboration.

Mitigation of Methane and Odor using a Pilot-Scale Engineered Biocover at a Landfill, South Korea

NASA Astrophysics Data System (ADS)

Bomin, K.; O, G. C.; Ryu, H. W.; Jeon, J. M.; Cho, K. S.

2016-12-01

Landfill is an important anthropogenic source of methane (CH4) and odorous gases. In South Korea, 37% (0.5 Tg/y) of annual anthropogenic CH4 emissions come from landfills, which represent the third largest source of anthropogenic CH4 emissions. Moreover, civil complaints on landfill odor have been gradually increased. Biocovers have been demonstrated as promising solutions to mitigate CH4 and odors from landfills. The pilot-scale biocover (10 m in length x 5 m in width x 1 m in depth) was constructed at a landfill, Gwangyang, South Korea. The mixture of soil and perlite was used as packing materials, and EG microbial agent was used as an inoculum source. Methane removal efficiencies were 21% 72% from Feburary to May. Based on the dilution-to-threshold ratios derived by the air dilution sensory test, the removal efficiencies for complex odor were ranged from 95% to 99%. The packing materials of biocover were sampled from each of the following depth intervals: 0-15 cm, 15-30 cm, and 30-50 cm, and CH4 and DMS degradation rates were measured in serum bottles experiment. CH4 and DMS average degradation rates were the fastest in the 15-30 cm depth. Average degradation rates of CH4 and DMS in the 15-30 cm depth were 208±2.68 and 82±3.04 μg·g dry soil-1·h-1, respectively. Specific degradation rate were calculated excluding the lag time. CH4 specific degradation rate was the fastest in the 0-15 cm depth (329±14.45 μg·g dry soil-1·h-1), while DMS specific degradation rate was the fastest in the 30-50 cm depth (106±6.93 μg·g dry soil-1·h-1). The filling materials of biocover were sampled during winter, spring and summer. And three samples were examined bacterial communities by 16S rRNA pyrosequencing analysis. In order to clarify the relationship between the community structures and CH4/odor concentration, network analysis using extended local similarity analysis (eLSA) was also conducted. According to a phylogenic analysis, Methylobacter (40.4 42.1%) and Flavobacterium (20.2 38.2%) were the most prevalent species in the pilot-scale biocover. Methylobacter (Methanotrophics of Type I) are responsible for methane oxidation and can be identified in the biocover.

Series Bosch System Development

NASA Technical Reports Server (NTRS)

Abney, Morgan B.; Evans, Christopher; Mansell, Matt; Swickrath, Michael

2012-01-01

State-of-the-art (SOA) carbon dioxide (CO2) reduction technology for the International Space Station produces methane as a byproduct. This methane is subsequently vented overboard. The associated loss of hydrogen ultimately reduces the mass of oxygen that can be recovered from CO2 in a closed-loop life support system. As an alternative to SOA CO2 reduction technology, NASA is exploring a Series-Bosch system capable of reducing CO2 with hydrogen to form water and solid carbon. This results in 100% theoretical recovery of oxygen from metabolic CO2. In the past, Bosch-based technology did not trade favorably against SOA technology due to a high power demand, low reaction efficiencies, concerns with carbon containment, and large resupply requirements necessary to replace expended catalyst cartridges. An alternative approach to Bosch technology, labeled "Series-Bosch," employs a new system design with optimized multi-stage reactors and a membrane-based separation and recycle capability. Multi-physics modeling of the first stage reactor, along with chemical process modeling of the integrated system, has resulted in a design with potential to trade significantly better than previous Bosch technology. The modeling process and resulting system architecture selection are discussed.

Volcanic Destabilisation of Methane Clathrate Hydrate on Titan: the Mechanism for Resupplying Atmospheric CH4?

NASA Astrophysics Data System (ADS)

Davies, Ashley; Sotin, C.; Choukroun, M.; Matson, D. L.; Johnson, T. V.

2013-10-01

Titan may have an upper crust rich in methane clathrates which would have formed early in Titan’s history [1-3]. The abundance of atmospheric methane, which has a limited lifetime, and the presence of 40Ar require replenishment over time. Volcanic processes may release these gases from Titan’s interior, although, so far, no conclusive evidence of an ongoing volcanic event has been observed: no “smoking gun” has been seen. Still, some process has recently supplied a considerable amount of methane to Titan’s atmosphere. We have investigated the emplacement of “cryolavas” of varying composition to quantify thermal exchange and lava solidification processes to model thermal wave penetration into a methane-rich substrate (see [4]), and to determine event detectability. Clathrate destabilisation releases methane and other trapped gases, such as argon. A 10-m-thick cryolava covering 100 km2 raises 3 x 108 m3 of substrate methane clathrates to destabilization temperature in ~108 s. With a density of 920 kg/m3, and ≈13% of the mass being methane, 4 x 1010 kg of methane is released. This is an impressive amount, but it would take 5 million similar events to yield the current mass of atmospheric methane. However, meeting Titan’s current global methane replenishment rate is feasible through the thermal interaction between cryolavas and methane clathrate deposits, but only (1) after the flow has solidified; (2) if cracks form, connecting surface to substrate; and (3) the cracks form while the temperature of the clathrates is greater than the destabilisation temperature. The relatively small scale of this activity may be hard to detect. This work was performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract to NASA. Choukroun, M. and Sotin, C. (2012) GRL, 39, L04201. [2] Tobie, G. et al. (2006) Nature, 440, 61-64. [3] Lunine, J. et al. (2009) Origin and Evolution of Titan, in Titan From Cassini-Huygens, ed. R. Brown et al., 35-59, Springer. [4] Davies, A. G. et al. (2013) LPSC 44 abstract 1681.

Disentangling the effects of CO2 and short-lived climate forcer mitigation.

PubMed

Rogelj, Joeri; Schaeffer, Michiel; Meinshausen, Malte; Shindell, Drew T; Hare, William; Klimont, Zbigniew; Velders, Guus J M; Amann, Markus; Schellnhuber, Hans Joachim

2014-11-18

Anthropogenic global warming is driven by emissions of a wide variety of radiative forcers ranging from very short-lived climate forcers (SLCFs), like black carbon, to very long-lived, like CO2. These species are often released from common sources and are therefore intricately linked. However, for reasons of simplification, this CO2-SLCF linkage was often disregarded in long-term projections of earlier studies. Here we explicitly account for CO2-SLCF linkages and show that the short- and long-term climate effects of many SLCF measures consistently become smaller in scenarios that keep warming to below 2 °C relative to preindustrial levels. Although long-term mitigation of methane and hydrofluorocarbons are integral parts of 2 °C scenarios, early action on these species mainly influences near-term temperatures and brings small benefits for limiting maximum warming relative to comparable reductions taking place later. Furthermore, we find that maximum 21st-century warming in 2 °C-consistent scenarios is largely unaffected by additional black-carbon-related measures because key emission sources are already phased-out through CO2 mitigation. Our study demonstrates the importance of coherently considering CO2-SLCF coevolutions. Failing to do so leads to strongly and consistently overestimating the effect of SLCF measures in climate stabilization scenarios. Our results reinforce that SLCF measures are to be considered complementary rather than a substitute for early and stringent CO2 mitigation. Near-term SLCF measures do not allow for more time for CO2 mitigation. We disentangle and resolve the distinct benefits across different species and therewith facilitate an integrated strategy for mitigating both short and long-term climate change.